USB: Moschip 7840 USB-Serial Driver
Paul B Schroeder [Fri, 1 Sep 2006 00:41:47 +0000 (19:41 -0500)]
Signed-off-by: Paul B Schroeder <pschroeder@uplogix.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/serial/Kconfig
drivers/usb/serial/Makefile
drivers/usb/serial/mos7840.c [new file with mode: 0644]

index e4df0ac..5076b9d 100644 (file)
@@ -422,6 +422,21 @@ config USB_SERIAL_MCT_U232
          To compile this driver as a module, choose M here: the
          module will be called mct_u232.
 
+config USB_SERIAL_MOS7840
+       tristate "USB Moschip 7840/7820 USB Serial Driver"
+       depends on USB_SERIAL
+       ---help---
+         Say Y here if you want to use a MCS7840 Quad-Serial or MCS7820
+         Dual-Serial port device from MosChip Semiconductor.
+
+         The MCS7840 and MCS7820 have been developed to connect a wide range
+         of standard serial devices to a USB host.  The MCS7840 has a USB
+         device controller connected to four (4) individual UARTs while the
+         MCS7820 controller connects to two (2) individual UARTs.
+
+         To compile this driver as a module, choose M here: the
+         module will be called mos7840.  If unsure, choose N.
+
 config USB_SERIAL_NAVMAN
        tristate "USB Navman GPS device"
        depends on USB_SERIAL
index 029e2a1..8dce833 100644 (file)
@@ -34,6 +34,7 @@ obj-$(CONFIG_USB_SERIAL_KEYSPAN_PDA)          += keyspan_pda.o
 obj-$(CONFIG_USB_SERIAL_KLSI)                  += kl5kusb105.o
 obj-$(CONFIG_USB_SERIAL_KOBIL_SCT)             += kobil_sct.o
 obj-$(CONFIG_USB_SERIAL_MCT_U232)              += mct_u232.o
+obj-$(CONFIG_USB_SERIAL_MOS7840)               += mos7840.o
 obj-$(CONFIG_USB_SERIAL_NAVMAN)                        += navman.o
 obj-$(CONFIG_USB_SERIAL_OMNINET)               += omninet.o
 obj-$(CONFIG_USB_SERIAL_OPTION)                        += option.o
diff --git a/drivers/usb/serial/mos7840.c b/drivers/usb/serial/mos7840.c
new file mode 100644 (file)
index 0000000..95bf571
--- /dev/null
@@ -0,0 +1,2962 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ * Clean ups from Moschip version and a few ioctl implementations by:
+ *     Paul B Schroeder <pschroeder "at" uplogix "dot" com>
+ *
+ * Originally based on drivers/usb/serial/io_edgeport.c which is:
+ *      Copyright (C) 2000 Inside Out Networks, All rights reserved.
+ *      Copyright (C) 2001-2002 Greg Kroah-Hartman <greg@kroah.com>
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/tty.h>
+#include <linux/tty_driver.h>
+#include <linux/tty_flip.h>
+#include <linux/module.h>
+#include <linux/serial.h>
+#include <linux/usb.h>
+#include <linux/usb/serial.h>
+#include <asm/uaccess.h>
+
+/*
+ * Version Information
+ */
+#define DRIVER_VERSION "1.3.1"
+#define DRIVER_DESC "Moschip 7840/7820 USB Serial Driver"
+
+/*
+ * 16C50 UART register defines
+ */
+
+#define LCR_BITS_5             0x00    /* 5 bits/char */
+#define LCR_BITS_6             0x01    /* 6 bits/char */
+#define LCR_BITS_7             0x02    /* 7 bits/char */
+#define LCR_BITS_8             0x03    /* 8 bits/char */
+#define LCR_BITS_MASK          0x03    /* Mask for bits/char field */
+
+#define LCR_STOP_1             0x00    /* 1 stop bit */
+#define LCR_STOP_1_5           0x04    /* 1.5 stop bits (if 5   bits/char) */
+#define LCR_STOP_2             0x04    /* 2 stop bits   (if 6-8 bits/char) */
+#define LCR_STOP_MASK          0x04    /* Mask for stop bits field */
+
+#define LCR_PAR_NONE           0x00    /* No parity */
+#define LCR_PAR_ODD            0x08    /* Odd parity */
+#define LCR_PAR_EVEN           0x18    /* Even parity */
+#define LCR_PAR_MARK           0x28    /* Force parity bit to 1 */
+#define LCR_PAR_SPACE          0x38    /* Force parity bit to 0 */
+#define LCR_PAR_MASK           0x38    /* Mask for parity field */
+
+#define LCR_SET_BREAK          0x40    /* Set Break condition */
+#define LCR_DL_ENABLE          0x80    /* Enable access to divisor latch */
+
+#define MCR_DTR                0x01    /* Assert DTR */
+#define MCR_RTS                0x02    /* Assert RTS */
+#define MCR_OUT1               0x04    /* Loopback only: Sets state of RI */
+#define MCR_MASTER_IE          0x08    /* Enable interrupt outputs */
+#define MCR_LOOPBACK           0x10    /* Set internal (digital) loopback mode */
+#define MCR_XON_ANY            0x20    /* Enable any char to exit XOFF mode */
+
+#define MOS7840_MSR_CTS        0x10    /* Current state of CTS */
+#define MOS7840_MSR_DSR        0x20    /* Current state of DSR */
+#define MOS7840_MSR_RI         0x40    /* Current state of RI */
+#define MOS7840_MSR_CD         0x80    /* Current state of CD */
+
+/*
+ * Defines used for sending commands to port
+ */
+
+#define WAIT_FOR_EVER   (HZ * 0 )      /* timeout urb is wait for ever */
+#define MOS_WDR_TIMEOUT (HZ * 5 )      /* default urb timeout */
+
+#define MOS_PORT1       0x0200
+#define MOS_PORT2       0x0300
+#define MOS_VENREG      0x0000
+#define MOS_MAX_PORT   0x02
+#define MOS_WRITE       0x0E
+#define MOS_READ        0x0D
+
+/* Requests */
+#define MCS_RD_RTYPE    0xC0
+#define MCS_WR_RTYPE    0x40
+#define MCS_RDREQ       0x0D
+#define MCS_WRREQ       0x0E
+#define MCS_CTRL_TIMEOUT        500
+#define VENDOR_READ_LENGTH      (0x01)
+
+#define MAX_NAME_LEN    64
+
+#define ZLP_REG1  0x3A         //Zero_Flag_Reg1    58
+#define ZLP_REG5  0x3E         //Zero_Flag_Reg5    62
+
+/* For higher baud Rates use TIOCEXBAUD */
+#define TIOCEXBAUD     0x5462
+
+/* vendor id and device id defines */
+
+#define USB_VENDOR_ID_MOSCHIP           0x9710
+#define MOSCHIP_DEVICE_ID_7840          0x7840
+#define MOSCHIP_DEVICE_ID_7820          0x7820
+
+/* Interrupt Rotinue Defines    */
+
+#define SERIAL_IIR_RLS      0x06
+#define SERIAL_IIR_MS       0x00
+
+/*
+ *  Emulation of the bit mask on the LINE STATUS REGISTER.
+ */
+#define SERIAL_LSR_DR       0x0001
+#define SERIAL_LSR_OE       0x0002
+#define SERIAL_LSR_PE       0x0004
+#define SERIAL_LSR_FE       0x0008
+#define SERIAL_LSR_BI       0x0010
+
+#define MOS_MSR_DELTA_CTS   0x10
+#define MOS_MSR_DELTA_DSR   0x20
+#define MOS_MSR_DELTA_RI    0x40
+#define MOS_MSR_DELTA_CD    0x80
+
+// Serial Port register Address
+#define INTERRUPT_ENABLE_REGISTER  ((__u16)(0x01))
+#define FIFO_CONTROL_REGISTER      ((__u16)(0x02))
+#define LINE_CONTROL_REGISTER      ((__u16)(0x03))
+#define MODEM_CONTROL_REGISTER     ((__u16)(0x04))
+#define LINE_STATUS_REGISTER       ((__u16)(0x05))
+#define MODEM_STATUS_REGISTER      ((__u16)(0x06))
+#define SCRATCH_PAD_REGISTER       ((__u16)(0x07))
+#define DIVISOR_LATCH_LSB          ((__u16)(0x00))
+#define DIVISOR_LATCH_MSB          ((__u16)(0x01))
+
+#define CLK_MULTI_REGISTER         ((__u16)(0x02))
+#define CLK_START_VALUE_REGISTER   ((__u16)(0x03))
+
+#define SERIAL_LCR_DLAB            ((__u16)(0x0080))
+
+/*
+ * URB POOL related defines
+ */
+#define NUM_URBS                        16     /* URB Count */
+#define URB_TRANSFER_BUFFER_SIZE        32     /* URB Size  */
+
+
+static struct usb_device_id moschip_port_id_table[] = {
+       {USB_DEVICE(USB_VENDOR_ID_MOSCHIP, MOSCHIP_DEVICE_ID_7840)},
+       {USB_DEVICE(USB_VENDOR_ID_MOSCHIP, MOSCHIP_DEVICE_ID_7820)},
+       {}                      /* terminating entry */
+};
+
+static __devinitdata struct usb_device_id moschip_id_table_combined[] = {
+       {USB_DEVICE(USB_VENDOR_ID_MOSCHIP, MOSCHIP_DEVICE_ID_7840)},
+       {USB_DEVICE(USB_VENDOR_ID_MOSCHIP, MOSCHIP_DEVICE_ID_7820)},
+       {}                      /* terminating entry */
+};
+
+MODULE_DEVICE_TABLE(usb, moschip_id_table_combined);
+
+/* This structure holds all of the local port information */
+
+struct moschip_port {
+       int port_num;           /*Actual port number in the device(1,2,etc) */
+       struct urb *write_urb;  /* write URB for this port */
+       struct urb *read_urb;   /* read URB for this port */
+       __u8 shadowLCR;         /* last LCR value received */
+       __u8 shadowMCR;         /* last MCR value received */
+       char open;
+       wait_queue_head_t wait_chase;   /* for handling sleeping while waiting for chase to finish */
+       wait_queue_head_t delta_msr_wait;       /* for handling sleeping while waiting for msr change to happen */
+       int delta_msr_cond;
+       struct async_icount icount;
+       struct usb_serial_port *port;   /* loop back to the owner of this object */
+
+       /*Offsets */
+       __u8 SpRegOffset;
+       __u8 ControlRegOffset;
+       __u8 DcrRegOffset;
+       //for processing control URBS in interrupt context
+       struct urb *control_urb;
+       char *ctrl_buf;
+       int MsrLsr;
+
+       struct urb *write_urb_pool[NUM_URBS];
+};
+
+
+static int debug;
+static int mos7840_num_ports;  //this says the number of ports in the device
+static int mos7840_num_open_ports;
+
+
+/*
+ * mos7840_set_reg_sync
+ *     To set the Control register by calling usb_fill_control_urb function
+ *     by passing usb_sndctrlpipe function as parameter.
+ */
+
+static int mos7840_set_reg_sync(struct usb_serial_port *port, __u16 reg,
+                               __u16 val)
+{
+       struct usb_device *dev = port->serial->dev;
+       val = val & 0x00ff;
+       dbg("mos7840_set_reg_sync offset is %x, value %x\n", reg, val);
+
+       return usb_control_msg(dev, usb_sndctrlpipe(dev, 0), MCS_WRREQ,
+                              MCS_WR_RTYPE, val, reg, NULL, 0,
+                              MOS_WDR_TIMEOUT);
+}
+
+/*
+ * mos7840_get_reg_sync
+ *     To set the Uart register by calling usb_fill_control_urb function by
+ *     passing usb_rcvctrlpipe function as parameter.
+ */
+
+static int mos7840_get_reg_sync(struct usb_serial_port *port, __u16 reg,
+                               __u16 * val)
+{
+       struct usb_device *dev = port->serial->dev;
+       int ret = 0;
+
+       ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), MCS_RDREQ,
+                             MCS_RD_RTYPE, 0, reg, val, VENDOR_READ_LENGTH,
+                             MOS_WDR_TIMEOUT);
+       dbg("mos7840_get_reg_sync offset is %x, return val %x\n", reg, *val);
+       *val = (*val) & 0x00ff;
+       return ret;
+}
+
+/*
+ * mos7840_set_uart_reg
+ *     To set the Uart register by calling usb_fill_control_urb function by
+ *     passing usb_sndctrlpipe function as parameter.
+ */
+
+static int mos7840_set_uart_reg(struct usb_serial_port *port, __u16 reg,
+                               __u16 val)
+{
+
+       struct usb_device *dev = port->serial->dev;
+       val = val & 0x00ff;
+       // For the UART control registers, the application number need to be Or'ed
+       if (mos7840_num_ports == 4) {
+               val |=
+                   (((__u16) port->number - (__u16) (port->serial->minor)) +
+                    1) << 8;
+               dbg("mos7840_set_uart_reg application number is %x\n", val);
+       } else {
+               if (((__u16) port->number - (__u16) (port->serial->minor)) == 0) {
+                       val |=
+                           (((__u16) port->number -
+                             (__u16) (port->serial->minor)) + 1) << 8;
+                       dbg("mos7840_set_uart_reg application number is %x\n",
+                           val);
+               } else {
+                       val |=
+                           (((__u16) port->number -
+                             (__u16) (port->serial->minor)) + 2) << 8;
+                       dbg("mos7840_set_uart_reg application number is %x\n",
+                           val);
+               }
+       }
+       return usb_control_msg(dev, usb_sndctrlpipe(dev, 0), MCS_WRREQ,
+                              MCS_WR_RTYPE, val, reg, NULL, 0,
+                              MOS_WDR_TIMEOUT);
+
+}
+
+/*
+ * mos7840_get_uart_reg
+ *     To set the Control register by calling usb_fill_control_urb function
+ *     by passing usb_rcvctrlpipe function as parameter.
+ */
+static int mos7840_get_uart_reg(struct usb_serial_port *port, __u16 reg,
+                               __u16 * val)
+{
+       struct usb_device *dev = port->serial->dev;
+       int ret = 0;
+       __u16 Wval;
+
+       //dbg("application number is %4x \n",(((__u16)port->number - (__u16)(port->serial->minor))+1)<<8);
+       /*Wval  is same as application number */
+       if (mos7840_num_ports == 4) {
+               Wval =
+                   (((__u16) port->number - (__u16) (port->serial->minor)) +
+                    1) << 8;
+               dbg("mos7840_get_uart_reg application number is %x\n", Wval);
+       } else {
+               if (((__u16) port->number - (__u16) (port->serial->minor)) == 0) {
+                       Wval =
+                           (((__u16) port->number -
+                             (__u16) (port->serial->minor)) + 1) << 8;
+                       dbg("mos7840_get_uart_reg application number is %x\n",
+                           Wval);
+               } else {
+                       Wval =
+                           (((__u16) port->number -
+                             (__u16) (port->serial->minor)) + 2) << 8;
+                       dbg("mos7840_get_uart_reg application number is %x\n",
+                           Wval);
+               }
+       }
+       ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), MCS_RDREQ,
+                             MCS_RD_RTYPE, Wval, reg, val, VENDOR_READ_LENGTH,
+                             MOS_WDR_TIMEOUT);
+       *val = (*val) & 0x00ff;
+       return ret;
+}
+
+static void mos7840_dump_serial_port(struct moschip_port *mos7840_port)
+{
+
+       dbg("***************************************\n");
+       dbg("SpRegOffset is %2x\n", mos7840_port->SpRegOffset);
+       dbg("ControlRegOffset is %2x \n", mos7840_port->ControlRegOffset);
+       dbg("DCRRegOffset is %2x \n", mos7840_port->DcrRegOffset);
+       dbg("***************************************\n");
+
+}
+
+/************************************************************************/
+/************************************************************************/
+/*             I N T E R F A C E   F U N C T I O N S                   */
+/*             I N T E R F A C E   F U N C T I O N S                   */
+/************************************************************************/
+/************************************************************************/
+
+static inline void mos7840_set_port_private(struct usb_serial_port *port,
+                                           struct moschip_port *data)
+{
+       usb_set_serial_port_data(port, (void *)data);
+}
+
+static inline struct moschip_port *mos7840_get_port_private(struct
+                                                           usb_serial_port
+                                                           *port)
+{
+       return (struct moschip_port *)usb_get_serial_port_data(port);
+}
+
+static int mos7840_handle_new_msr(struct moschip_port *port, __u8 new_msr)
+{
+       struct moschip_port *mos7840_port;
+       struct async_icount *icount;
+       mos7840_port = port;
+       icount = &mos7840_port->icount;
+       if (new_msr &
+           (MOS_MSR_DELTA_CTS | MOS_MSR_DELTA_DSR | MOS_MSR_DELTA_RI |
+            MOS_MSR_DELTA_CD)) {
+               icount = &mos7840_port->icount;
+
+               /* update input line counters */
+               if (new_msr & MOS_MSR_DELTA_CTS) {
+                       icount->cts++;
+               }
+               if (new_msr & MOS_MSR_DELTA_DSR) {
+                       icount->dsr++;
+               }
+               if (new_msr & MOS_MSR_DELTA_CD) {
+                       icount->dcd++;
+               }
+               if (new_msr & MOS_MSR_DELTA_RI) {
+                       icount->rng++;
+               }
+       }
+
+       return 0;
+}
+
+static int mos7840_handle_new_lsr(struct moschip_port *port, __u8 new_lsr)
+{
+       struct async_icount *icount;
+
+       dbg("%s - %02x", __FUNCTION__, new_lsr);
+
+       if (new_lsr & SERIAL_LSR_BI) {
+               //
+               // Parity and Framing errors only count if they
+               // occur exclusive of a break being
+               // received.
+               //
+               new_lsr &= (__u8) (SERIAL_LSR_OE | SERIAL_LSR_BI);
+       }
+
+       /* update input line counters */
+       icount = &port->icount;
+       if (new_lsr & SERIAL_LSR_BI) {
+               icount->brk++;
+       }
+       if (new_lsr & SERIAL_LSR_OE) {
+               icount->overrun++;
+       }
+       if (new_lsr & SERIAL_LSR_PE) {
+               icount->parity++;
+       }
+       if (new_lsr & SERIAL_LSR_FE) {
+               icount->frame++;
+       }
+
+       return 0;
+}
+
+/************************************************************************/
+/************************************************************************/
+/*            U S B  C A L L B A C K   F U N C T I O N S                */
+/*            U S B  C A L L B A C K   F U N C T I O N S                */
+/************************************************************************/
+/************************************************************************/
+
+static void mos7840_control_callback(struct urb *urb, struct pt_regs *regs)
+{
+       unsigned char *data;
+       struct moschip_port *mos7840_port;
+       __u8 regval = 0x0;
+
+       if (!urb) {
+               dbg("%s", "Invalid Pointer !!!!:\n");
+               return;
+       }
+
+       switch (urb->status) {
+       case 0:
+               /* success */
+               break;
+       case -ECONNRESET:
+       case -ENOENT:
+       case -ESHUTDOWN:
+               /* this urb is terminated, clean up */
+               dbg("%s - urb shutting down with status: %d", __FUNCTION__,
+                   urb->status);
+               return;
+       default:
+               dbg("%s - nonzero urb status received: %d", __FUNCTION__,
+                   urb->status);
+               goto exit;
+       }
+
+       mos7840_port = (struct moschip_port *)urb->context;
+
+       dbg("%s urb buffer size is %d\n", __FUNCTION__, urb->actual_length);
+       dbg("%s mos7840_port->MsrLsr is %d port %d\n", __FUNCTION__,
+           mos7840_port->MsrLsr, mos7840_port->port_num);
+       data = urb->transfer_buffer;
+       regval = (__u8) data[0];
+       dbg("%s data is %x\n", __FUNCTION__, regval);
+       if (mos7840_port->MsrLsr == 0)
+               mos7840_handle_new_msr(mos7840_port, regval);
+       else if (mos7840_port->MsrLsr == 1)
+               mos7840_handle_new_lsr(mos7840_port, regval);
+
+      exit:
+       return;
+}
+
+static int mos7840_get_reg(struct moschip_port *mcs, __u16 Wval, __u16 reg,
+                          __u16 * val)
+{
+       struct usb_device *dev = mcs->port->serial->dev;
+       struct usb_ctrlrequest *dr = NULL;
+       unsigned char *buffer = NULL;
+       int ret = 0;
+       buffer = (__u8 *) mcs->ctrl_buf;
+
+//      dr=(struct usb_ctrlrequest *)(buffer);
+       dr = (void *)(buffer + 2);
+       dr->bRequestType = MCS_RD_RTYPE;
+       dr->bRequest = MCS_RDREQ;
+       dr->wValue = cpu_to_le16(Wval); //0;
+       dr->wIndex = cpu_to_le16(reg);
+       dr->wLength = cpu_to_le16(2);
+
+       usb_fill_control_urb(mcs->control_urb, dev, usb_rcvctrlpipe(dev, 0),
+                            (unsigned char *)dr, buffer, 2,
+                            mos7840_control_callback, mcs);
+       mcs->control_urb->transfer_buffer_length = 2;
+       ret = usb_submit_urb(mcs->control_urb, GFP_ATOMIC);
+       return ret;
+}
+
+/*****************************************************************************
+ * mos7840_interrupt_callback
+ *     this is the callback function for when we have received data on the
+ *     interrupt endpoint.
+ *****************************************************************************/
+
+static void mos7840_interrupt_callback(struct urb *urb, struct pt_regs *regs)
+{
+       int result;
+       int length;
+       struct moschip_port *mos7840_port;
+       struct usb_serial *serial;
+       __u16 Data;
+       unsigned char *data;
+       __u8 sp[5], st;
+       int i;
+       __u16 wval;
+
+       dbg("%s", " : Entering\n");
+       if (!urb) {
+               dbg("%s", "Invalid Pointer !!!!:\n");
+               return;
+       }
+
+       switch (urb->status) {
+       case 0:
+               /* success */
+               break;
+       case -ECONNRESET:
+       case -ENOENT:
+       case -ESHUTDOWN:
+               /* this urb is terminated, clean up */
+               dbg("%s - urb shutting down with status: %d", __FUNCTION__,
+                   urb->status);
+               return;
+       default:
+               dbg("%s - nonzero urb status received: %d", __FUNCTION__,
+                   urb->status);
+               goto exit;
+       }
+
+       length = urb->actual_length;
+       data = urb->transfer_buffer;
+
+       serial = (struct usb_serial *)urb->context;
+
+       /* Moschip get 5 bytes
+        * Byte 1 IIR Port 1 (port.number is 0)
+        * Byte 2 IIR Port 2 (port.number is 1)
+        * Byte 3 IIR Port 3 (port.number is 2)
+        * Byte 4 IIR Port 4 (port.number is 3)
+        * Byte 5 FIFO status for both */
+
+       if (length && length > 5) {
+               dbg("%s \n", "Wrong data !!!");
+               return;
+       }
+
+       sp[0] = (__u8) data[0];
+       sp[1] = (__u8) data[1];
+       sp[2] = (__u8) data[2];
+       sp[3] = (__u8) data[3];
+       st = (__u8) data[4];
+
+       for (i = 0; i < serial->num_ports; i++) {
+               mos7840_port = mos7840_get_port_private(serial->port[i]);
+               wval =
+                   (((__u16) serial->port[i]->number -
+                     (__u16) (serial->minor)) + 1) << 8;
+               if (mos7840_port->open) {
+                       if (sp[i] & 0x01) {
+                               dbg("SP%d No Interrupt !!!\n", i);
+                       } else {
+                               switch (sp[i] & 0x0f) {
+                               case SERIAL_IIR_RLS:
+                                       dbg("Serial Port %d: Receiver status error or ", i);
+                                       dbg("address bit detected in 9-bit mode\n");
+                                       mos7840_port->MsrLsr = 1;
+                                       mos7840_get_reg(mos7840_port, wval,
+                                                       LINE_STATUS_REGISTER,
+                                                       &Data);
+                                       break;
+                               case SERIAL_IIR_MS:
+                                       dbg("Serial Port %d: Modem status change\n", i);
+                                       mos7840_port->MsrLsr = 0;
+                                       mos7840_get_reg(mos7840_port, wval,
+                                                       MODEM_STATUS_REGISTER,
+                                                       &Data);
+                                       break;
+                               }
+                       }
+               }
+       }
+      exit:
+       result = usb_submit_urb(urb, GFP_ATOMIC);
+       if (result) {
+               dev_err(&urb->dev->dev,
+                       "%s - Error %d submitting interrupt urb\n",
+                       __FUNCTION__, result);
+       }
+
+       return;
+
+}
+
+static int mos7840_port_paranoia_check(struct usb_serial_port *port,
+                                      const char *function)
+{
+       if (!port) {
+               dbg("%s - port == NULL", function);
+               return -1;
+       }
+       if (!port->serial) {
+               dbg("%s - port->serial == NULL", function);
+               return -1;
+       }
+
+       return 0;
+}
+
+/* Inline functions to check the sanity of a pointer that is passed to us */
+static int mos7840_serial_paranoia_check(struct usb_serial *serial,
+                                        const char *function)
+{
+       if (!serial) {
+               dbg("%s - serial == NULL", function);
+               return -1;
+       }
+       if (!serial->type) {
+               dbg("%s - serial->type == NULL!", function);
+               return -1;
+       }
+
+       return 0;
+}
+
+static struct usb_serial *mos7840_get_usb_serial(struct usb_serial_port *port,
+                                                const char *function)
+{
+       /* if no port was specified, or it fails a paranoia check */
+       if (!port ||
+           mos7840_port_paranoia_check(port, function) ||
+           mos7840_serial_paranoia_check(port->serial, function)) {
+               /* then say that we don't have a valid usb_serial thing, which will                  * end up genrating -ENODEV return values */
+               return NULL;
+       }
+
+       return port->serial;
+}
+
+/*****************************************************************************
+ * mos7840_bulk_in_callback
+ *     this is the callback function for when we have received data on the
+ *     bulk in endpoint.
+ *****************************************************************************/
+
+static void mos7840_bulk_in_callback(struct urb *urb, struct pt_regs *regs)
+{
+       int status;
+       unsigned char *data;
+       struct usb_serial *serial;
+       struct usb_serial_port *port;
+       struct moschip_port *mos7840_port;
+       struct tty_struct *tty;
+
+       if (!urb) {
+               dbg("%s", "Invalid Pointer !!!!:\n");
+               return;
+       }
+
+       if (urb->status) {
+               dbg("nonzero read bulk status received: %d", urb->status);
+               return;
+       }
+
+       mos7840_port = (struct moschip_port *)urb->context;
+       if (!mos7840_port) {
+               dbg("%s", "NULL mos7840_port pointer \n");
+               return;
+       }
+
+       port = (struct usb_serial_port *)mos7840_port->port;
+       if (mos7840_port_paranoia_check(port, __FUNCTION__)) {
+               dbg("%s", "Port Paranoia failed \n");
+               return;
+       }
+
+       serial = mos7840_get_usb_serial(port, __FUNCTION__);
+       if (!serial) {
+               dbg("%s\n", "Bad serial pointer ");
+               return;
+       }
+
+       dbg("%s\n", "Entering... \n");
+
+       data = urb->transfer_buffer;
+
+       dbg("%s", "Entering ........... \n");
+
+       if (urb->actual_length) {
+               tty = mos7840_port->port->tty;
+               if (tty) {
+                       tty_buffer_request_room(tty, urb->actual_length);
+                       tty_insert_flip_string(tty, data, urb->actual_length);
+                       dbg(" %s \n", data);
+                       tty_flip_buffer_push(tty);
+               }
+               mos7840_port->icount.rx += urb->actual_length;
+               dbg("mos7840_port->icount.rx is %d:\n",
+                   mos7840_port->icount.rx);
+       }
+
+       if (!mos7840_port->read_urb) {
+               dbg("%s", "URB KILLED !!!\n");
+               return;
+       }
+
+       if (mos7840_port->read_urb->status != -EINPROGRESS) {
+               mos7840_port->read_urb->dev = serial->dev;
+
+               status = usb_submit_urb(mos7840_port->read_urb, GFP_ATOMIC);
+
+               if (status) {
+                       dbg(" usb_submit_urb(read bulk) failed, status = %d",
+                           status);
+               }
+       }
+}
+
+/*****************************************************************************
+ * mos7840_bulk_out_data_callback
+ *     this is the callback function for when we have finished sending serial data
+ *     on the bulk out endpoint.
+ *****************************************************************************/
+
+static void mos7840_bulk_out_data_callback(struct urb *urb,
+                                          struct pt_regs *regs)
+{
+       struct moschip_port *mos7840_port;
+       struct tty_struct *tty;
+       if (!urb) {
+               dbg("%s", "Invalid Pointer !!!!:\n");
+               return;
+       }
+
+       if (urb->status) {
+               dbg("nonzero write bulk status received:%d\n", urb->status);
+               return;
+       }
+
+       mos7840_port = (struct moschip_port *)urb->context;
+       if (!mos7840_port) {
+               dbg("%s", "NULL mos7840_port pointer \n");
+               return;
+       }
+
+       if (mos7840_port_paranoia_check(mos7840_port->port, __FUNCTION__)) {
+               dbg("%s", "Port Paranoia failed \n");
+               return;
+       }
+
+       dbg("%s \n", "Entering .........");
+
+       tty = mos7840_port->port->tty;
+
+       if (tty && mos7840_port->open) {
+               /* let the tty driver wakeup if it has a special *
+                * write_wakeup function                         */
+
+               if ((tty->flags & (1 << TTY_DO_WRITE_WAKEUP))
+                   && tty->ldisc.write_wakeup) {
+                       (tty->ldisc.write_wakeup) (tty);
+               }
+
+               /* tell the tty driver that something has changed */
+               wake_up_interruptible(&tty->write_wait);
+       }
+
+}
+
+/************************************************************************/
+/*       D R I V E R  T T Y  I N T E R F A C E  F U N C T I O N S       */
+/************************************************************************/
+#ifdef MCSSerialProbe
+static int mos7840_serial_probe(struct usb_serial *serial,
+                               const struct usb_device_id *id)
+{
+
+       /*need to implement the mode_reg reading and updating\
+          structures usb_serial_ device_type\
+          (i.e num_ports, num_bulkin,bulkout etc) */
+       /* Also we can update the changes  attach */
+       return 1;
+}
+#endif
+
+/*****************************************************************************
+ * mos7840_open
+ *     this function is called by the tty driver when a port is opened
+ *     If successful, we return 0
+ *     Otherwise we return a negative error number.
+ *****************************************************************************/
+
+static int mos7840_open(struct usb_serial_port *port, struct file *filp)
+{
+       int response;
+       int j;
+       struct usb_serial *serial;
+       struct urb *urb;
+       __u16 Data;
+       int status;
+       struct moschip_port *mos7840_port;
+
+       if (mos7840_port_paranoia_check(port, __FUNCTION__)) {
+               dbg("%s", "Port Paranoia failed \n");
+               return -ENODEV;
+       }
+
+       mos7840_num_open_ports++;
+       serial = port->serial;
+
+       if (mos7840_serial_paranoia_check(serial, __FUNCTION__)) {
+               dbg("%s", "Serial Paranoia failed \n");
+               return -ENODEV;
+       }
+
+       mos7840_port = mos7840_get_port_private(port);
+
+       if (mos7840_port == NULL)
+               return -ENODEV;
+
+       usb_clear_halt(serial->dev, port->write_urb->pipe);
+       usb_clear_halt(serial->dev, port->read_urb->pipe);
+
+       /* Initialising the write urb pool */
+       for (j = 0; j < NUM_URBS; ++j) {
+               urb = usb_alloc_urb(0, SLAB_ATOMIC);
+               mos7840_port->write_urb_pool[j] = urb;
+
+               if (urb == NULL) {
+                       err("No more urbs???");
+                       continue;
+               }
+
+               urb->transfer_buffer = NULL;
+               urb->transfer_buffer =
+                   kmalloc(URB_TRANSFER_BUFFER_SIZE, GFP_KERNEL);
+               if (!urb->transfer_buffer) {
+                       err("%s-out of memory for urb buffers.", __FUNCTION__);
+                       continue;
+               }
+       }
+
+/*****************************************************************************
+ * Initialize MCS7840 -- Write Init values to corresponding Registers
+ *
+ * Register Index
+ * 1 : IER
+ * 2 : FCR
+ * 3 : LCR
+ * 4 : MCR
+ *
+ * 0x08 : SP1/2 Control Reg
+ *****************************************************************************/
+
+//NEED to check the following Block
+
+       status = 0;
+       Data = 0x0;
+       status = mos7840_get_reg_sync(port, mos7840_port->SpRegOffset, &Data);
+       if (status < 0) {
+               dbg("Reading Spreg failed\n");
+               return -1;
+       }
+       Data |= 0x80;
+       status = mos7840_set_reg_sync(port, mos7840_port->SpRegOffset, Data);
+       if (status < 0) {
+               dbg("writing Spreg failed\n");
+               return -1;
+       }
+
+       Data &= ~0x80;
+       status = mos7840_set_reg_sync(port, mos7840_port->SpRegOffset, Data);
+       if (status < 0) {
+               dbg("writing Spreg failed\n");
+               return -1;
+       }
+//End of block to be checked
+
+       status = 0;
+       Data = 0x0;
+       status =
+           mos7840_get_reg_sync(port, mos7840_port->ControlRegOffset, &Data);
+       if (status < 0) {
+               dbg("Reading Controlreg failed\n");
+               return -1;
+       }
+       Data |= 0x08;           //Driver done bit
+       Data |= 0x20;           //rx_disable
+       status = 0;
+       status =
+           mos7840_set_reg_sync(port, mos7840_port->ControlRegOffset, Data);
+       if (status < 0) {
+               dbg("writing Controlreg failed\n");
+               return -1;
+       }
+       //do register settings here
+       // Set all regs to the device default values.
+       ////////////////////////////////////
+       // First Disable all interrupts.
+       ////////////////////////////////////
+
+       Data = 0x00;
+       status = 0;
+       status = mos7840_set_uart_reg(port, INTERRUPT_ENABLE_REGISTER, Data);
+       if (status < 0) {
+               dbg("disableing interrupts failed\n");
+               return -1;
+       }
+       // Set FIFO_CONTROL_REGISTER to the default value
+       Data = 0x00;
+       status = 0;
+       status = mos7840_set_uart_reg(port, FIFO_CONTROL_REGISTER, Data);
+       if (status < 0) {
+               dbg("Writing FIFO_CONTROL_REGISTER  failed\n");
+               return -1;
+       }
+
+       Data = 0xcf;
+       status = 0;
+       status = mos7840_set_uart_reg(port, FIFO_CONTROL_REGISTER, Data);
+       if (status < 0) {
+               dbg("Writing FIFO_CONTROL_REGISTER  failed\n");
+               return -1;
+       }
+
+       Data = 0x03;
+       status = 0;
+       status = mos7840_set_uart_reg(port, LINE_CONTROL_REGISTER, Data);
+       mos7840_port->shadowLCR = Data;
+
+       Data = 0x0b;
+       status = 0;
+       status = mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER, Data);
+       mos7840_port->shadowMCR = Data;
+
+       Data = 0x00;
+       status = 0;
+       status = mos7840_get_uart_reg(port, LINE_CONTROL_REGISTER, &Data);
+       mos7840_port->shadowLCR = Data;
+
+       Data |= SERIAL_LCR_DLAB;        //data latch enable in LCR 0x80
+       status = 0;
+       status = mos7840_set_uart_reg(port, LINE_CONTROL_REGISTER, Data);
+
+       Data = 0x0c;
+       status = 0;
+       status = mos7840_set_uart_reg(port, DIVISOR_LATCH_LSB, Data);
+
+       Data = 0x0;
+       status = 0;
+       status = mos7840_set_uart_reg(port, DIVISOR_LATCH_MSB, Data);
+
+       Data = 0x00;
+       status = 0;
+       status = mos7840_get_uart_reg(port, LINE_CONTROL_REGISTER, &Data);
+
+       Data = Data & ~SERIAL_LCR_DLAB;
+       status = 0;
+       status = mos7840_set_uart_reg(port, LINE_CONTROL_REGISTER, Data);
+       mos7840_port->shadowLCR = Data;
+
+       //clearing Bulkin and Bulkout Fifo
+       Data = 0x0;
+       status = 0;
+       status = mos7840_get_reg_sync(port, mos7840_port->SpRegOffset, &Data);
+
+       Data = Data | 0x0c;
+       status = 0;
+       status = mos7840_set_reg_sync(port, mos7840_port->SpRegOffset, Data);
+
+       Data = Data & ~0x0c;
+       status = 0;
+       status = mos7840_set_reg_sync(port, mos7840_port->SpRegOffset, Data);
+       //Finally enable all interrupts
+       Data = 0x0;
+       Data = 0x0c;
+       status = 0;
+       status = mos7840_set_uart_reg(port, INTERRUPT_ENABLE_REGISTER, Data);
+
+       //clearing rx_disable
+       Data = 0x0;
+       status = 0;
+       status =
+           mos7840_get_reg_sync(port, mos7840_port->ControlRegOffset, &Data);
+       Data = Data & ~0x20;
+       status = 0;
+       status =
+           mos7840_set_reg_sync(port, mos7840_port->ControlRegOffset, Data);
+
+       // rx_negate
+       Data = 0x0;
+       status = 0;
+       status =
+           mos7840_get_reg_sync(port, mos7840_port->ControlRegOffset, &Data);
+       Data = Data | 0x10;
+       status = 0;
+       status =
+           mos7840_set_reg_sync(port, mos7840_port->ControlRegOffset, Data);
+
+       /* force low_latency on so that our tty_push actually forces *
+        * the data through,otherwise it is scheduled, and with      *
+        * high data rates (like with OHCI) data can get lost.       */
+
+       if (port->tty)
+               port->tty->low_latency = 1;
+/* Check to see if we've set up our endpoint info yet    *
+     * (can't set it up in mos7840_startup as the structures *
+     * were not set up at that time.)                        */
+       if (mos7840_num_open_ports == 1) {
+               if (serial->port[0]->interrupt_in_buffer == NULL) {
+
+                       /* set up interrupt urb */
+
+                       usb_fill_int_urb(serial->port[0]->interrupt_in_urb,
+                                        serial->dev,
+                                        usb_rcvintpipe(serial->dev,
+                                                       serial->port[0]->
+                                                       interrupt_in_endpointAddress),
+                                        serial->port[0]->interrupt_in_buffer,
+                                        serial->port[0]->interrupt_in_urb->
+                                        transfer_buffer_length,
+                                        mos7840_interrupt_callback,
+                                        serial,
+                                        serial->port[0]->interrupt_in_urb->
+                                        interval);
+
+                       /* start interrupt read for mos7840               *
+                        * will continue as long as mos7840 is connected  */
+
+                       response =
+                           usb_submit_urb(serial->port[0]->interrupt_in_urb,
+                                          GFP_KERNEL);
+                       if (response) {
+                               err("%s - Error %d submitting interrupt urb",
+                                   __FUNCTION__, response);
+                       }
+
+               }
+
+       }
+
+       /* see if we've set up our endpoint info yet   *
+        * (can't set it up in mos7840_startup as the  *
+        * structures were not set up at that time.)   */
+
+       dbg("port number is %d \n", port->number);
+       dbg("serial number is %d \n", port->serial->minor);
+       dbg("Bulkin endpoint is %d \n", port->bulk_in_endpointAddress);
+       dbg("BulkOut endpoint is %d \n", port->bulk_out_endpointAddress);
+       dbg("Interrupt endpoint is %d \n", port->interrupt_in_endpointAddress);
+       dbg("port's number in the device is %d\n", mos7840_port->port_num);
+       mos7840_port->read_urb = port->read_urb;
+
+       /* set up our bulk in urb */
+
+       usb_fill_bulk_urb(mos7840_port->read_urb,
+                         serial->dev,
+                         usb_rcvbulkpipe(serial->dev,
+                                         port->bulk_in_endpointAddress),
+                         port->bulk_in_buffer,
+                         mos7840_port->read_urb->transfer_buffer_length,
+                         mos7840_bulk_in_callback, mos7840_port);
+
+       dbg("mos7840_open: bulkin endpoint is %d\n",
+           port->bulk_in_endpointAddress);
+       response = usb_submit_urb(mos7840_port->read_urb, GFP_KERNEL);
+       if (response) {
+               err("%s - Error %d submitting control urb", __FUNCTION__,
+                   response);
+       }
+
+       /* initialize our wait queues */
+       init_waitqueue_head(&mos7840_port->wait_chase);
+       init_waitqueue_head(&mos7840_port->delta_msr_wait);
+
+       /* initialize our icount structure */
+       memset(&(mos7840_port->icount), 0x00, sizeof(mos7840_port->icount));
+
+       /* initialize our port settings */
+       mos7840_port->shadowMCR = MCR_MASTER_IE;        /* Must set to enable ints! */
+       /* send a open port command */
+       mos7840_port->open = 1;
+       //mos7840_change_port_settings(mos7840_port,old_termios);
+       mos7840_port->icount.tx = 0;
+       mos7840_port->icount.rx = 0;
+
+       dbg("\n\nusb_serial serial:%x       mos7840_port:%x\n      usb_serial_port port:%x\n\n", (unsigned int)serial, (unsigned int)mos7840_port, (unsigned int)port);
+
+       return 0;
+
+}
+
+/*****************************************************************************
+ * mos7840_chars_in_buffer
+ *     this function is called by the tty driver when it wants to know how many
+ *     bytes of data we currently have outstanding in the port (data that has
+ *     been written, but hasn't made it out the port yet)
+ *     If successful, we return the number of bytes left to be written in the
+ *     system,
+ *     Otherwise we return a negative error number.
+ *****************************************************************************/
+
+static int mos7840_chars_in_buffer(struct usb_serial_port *port)
+{
+       int i;
+       int chars = 0;
+       struct moschip_port *mos7840_port;
+
+       dbg("%s \n", " mos7840_chars_in_buffer:entering ...........");
+
+       if (mos7840_port_paranoia_check(port, __FUNCTION__)) {
+               dbg("%s", "Invalid port \n");
+               return -1;
+       }
+
+       mos7840_port = mos7840_get_port_private(port);
+       if (mos7840_port == NULL) {
+               dbg("%s \n", "mos7840_break:leaving ...........");
+               return -1;
+       }
+
+       for (i = 0; i < NUM_URBS; ++i) {
+               if (mos7840_port->write_urb_pool[i]->status == -EINPROGRESS) {
+                       chars += URB_TRANSFER_BUFFER_SIZE;
+               }
+       }
+       dbg("%s - returns %d", __FUNCTION__, chars);
+       return (chars);
+
+}
+
+/************************************************************************
+ *
+ * mos7840_block_until_tx_empty
+ *
+ *     This function will block the close until one of the following:
+ *             1. TX count are 0
+ *             2. The mos7840 has stopped
+ *             3. A timout of 3 seconds without activity has expired
+ *
+ ************************************************************************/
+static void mos7840_block_until_tx_empty(struct moschip_port *mos7840_port)
+{
+       int timeout = HZ / 10;
+       int wait = 30;
+       int count;
+
+       while (1) {
+
+               count = mos7840_chars_in_buffer(mos7840_port->port);
+
+               /* Check for Buffer status */
+               if (count <= 0) {
+                       return;
+               }
+
+               /* Block the thread for a while */
+               interruptible_sleep_on_timeout(&mos7840_port->wait_chase,
+                                              timeout);
+
+               /* No activity.. count down section */
+               wait--;
+               if (wait == 0) {
+                       dbg("%s - TIMEOUT", __FUNCTION__);
+                       return;
+               } else {
+                       /* Reset timout value back to seconds */
+                       wait = 30;
+               }
+       }
+}
+
+/*****************************************************************************
+ * mos7840_close
+ *     this function is called by the tty driver when a port is closed
+ *****************************************************************************/
+
+static void mos7840_close(struct usb_serial_port *port, struct file *filp)
+{
+       struct usb_serial *serial;
+       struct moschip_port *mos7840_port;
+       int j;
+       __u16 Data;
+
+       dbg("%s\n", "mos7840_close:entering...");
+
+       if (mos7840_port_paranoia_check(port, __FUNCTION__)) {
+               dbg("%s", "Port Paranoia failed \n");
+               return;
+       }
+
+       serial = mos7840_get_usb_serial(port, __FUNCTION__);
+       if (!serial) {
+               dbg("%s", "Serial Paranoia failed \n");
+               return;
+       }
+
+       mos7840_port = mos7840_get_port_private(port);
+
+       if (mos7840_port == NULL) {
+               return;
+       }
+
+       for (j = 0; j < NUM_URBS; ++j)
+               usb_kill_urb(mos7840_port->write_urb_pool[j]);
+
+       /* Freeing Write URBs */
+       for (j = 0; j < NUM_URBS; ++j) {
+               if (mos7840_port->write_urb_pool[j]) {
+                       if (mos7840_port->write_urb_pool[j]->transfer_buffer)
+                               kfree(mos7840_port->write_urb_pool[j]->
+                                     transfer_buffer);
+
+                       usb_free_urb(mos7840_port->write_urb_pool[j]);
+               }
+       }
+
+       if (serial->dev) {
+               /* flush and block until tx is empty */
+               mos7840_block_until_tx_empty(mos7840_port);
+       }
+
+       /* While closing port, shutdown all bulk read, write  *
+        * and interrupt read if they exists                  */
+       if (serial->dev) {
+
+               if (mos7840_port->write_urb) {
+                       dbg("%s", "Shutdown bulk write\n");
+                       usb_kill_urb(mos7840_port->write_urb);
+               }
+
+               if (mos7840_port->read_urb) {
+                       dbg("%s", "Shutdown bulk read\n");
+                       usb_kill_urb(mos7840_port->read_urb);
+               }
+               if ((&mos7840_port->control_urb)) {
+                       dbg("%s", "Shutdown control read\n");
+                       //      usb_kill_urb (mos7840_port->control_urb);
+
+               }
+       }
+//              if(mos7840_port->ctrl_buf != NULL)
+//                      kfree(mos7840_port->ctrl_buf);
+       mos7840_num_open_ports--;
+       dbg("mos7840_num_open_ports in close%d:in port%d\n",
+           mos7840_num_open_ports, port->number);
+       if (mos7840_num_open_ports == 0) {
+               if (serial->port[0]->interrupt_in_urb) {
+                       dbg("%s", "Shutdown interrupt_in_urb\n");
+               }
+       }
+
+       if (mos7840_port->write_urb) {
+               /* if this urb had a transfer buffer already (old tx) free it */
+
+               if (mos7840_port->write_urb->transfer_buffer != NULL) {
+                       kfree(mos7840_port->write_urb->transfer_buffer);
+               }
+               usb_free_urb(mos7840_port->write_urb);
+       }
+
+       Data = 0x0;
+       mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER, Data);
+
+       Data = 0x00;
+       mos7840_set_uart_reg(port, INTERRUPT_ENABLE_REGISTER, Data);
+
+       mos7840_port->open = 0;
+
+       dbg("%s \n", "Leaving ............");
+}
+
+/************************************************************************
+ *
+ * mos7840_block_until_chase_response
+ *
+ *     This function will block the close until one of the following:
+ *             1. Response to our Chase comes from mos7840
+ *             2. A timout of 10 seconds without activity has expired
+ *                (1K of mos7840 data @ 2400 baud ==> 4 sec to empty)
+ *
+ ************************************************************************/
+
+static void mos7840_block_until_chase_response(struct moschip_port
+                                              *mos7840_port)
+{
+       int timeout = 1 * HZ;
+       int wait = 10;
+       int count;
+
+       while (1) {
+               count = mos7840_chars_in_buffer(mos7840_port->port);
+
+               /* Check for Buffer status */
+               if (count <= 0) {
+                       return;
+               }
+
+               /* Block the thread for a while */
+               interruptible_sleep_on_timeout(&mos7840_port->wait_chase,
+                                              timeout);
+               /* No activity.. count down section */
+               wait--;
+               if (wait == 0) {
+                       dbg("%s - TIMEOUT", __FUNCTION__);
+                       return;
+               } else {
+                       /* Reset timout value back to seconds */
+                       wait = 10;
+               }
+       }
+
+}
+
+/*****************************************************************************
+ * mos7840_break
+ *     this function sends a break to the port
+ *****************************************************************************/
+static void mos7840_break(struct usb_serial_port *port, int break_state)
+{
+       unsigned char data;
+       struct usb_serial *serial;
+       struct moschip_port *mos7840_port;
+
+       dbg("%s \n", "Entering ...........");
+       dbg("mos7840_break: Start\n");
+
+       if (mos7840_port_paranoia_check(port, __FUNCTION__)) {
+               dbg("%s", "Port Paranoia failed \n");
+               return;
+       }
+
+       serial = mos7840_get_usb_serial(port, __FUNCTION__);
+       if (!serial) {
+               dbg("%s", "Serial Paranoia failed \n");
+               return;
+       }
+
+       mos7840_port = mos7840_get_port_private(port);
+
+       if (mos7840_port == NULL) {
+               return;
+       }
+
+       if (serial->dev) {
+
+               /* flush and block until tx is empty */
+               mos7840_block_until_chase_response(mos7840_port);
+       }
+
+       if (break_state == -1) {
+               data = mos7840_port->shadowLCR | LCR_SET_BREAK;
+       } else {
+               data = mos7840_port->shadowLCR & ~LCR_SET_BREAK;
+       }
+
+       mos7840_port->shadowLCR = data;
+       dbg("mcs7840_break mos7840_port->shadowLCR is %x\n",
+           mos7840_port->shadowLCR);
+       mos7840_set_uart_reg(port, LINE_CONTROL_REGISTER,
+                            mos7840_port->shadowLCR);
+
+       return;
+}
+
+/*****************************************************************************
+ * mos7840_write_room
+ *     this function is called by the tty driver when it wants to know how many
+ *     bytes of data we can accept for a specific port.
+ *     If successful, we return the amount of room that we have for this port
+ *     Otherwise we return a negative error number.
+ *****************************************************************************/
+
+static int mos7840_write_room(struct usb_serial_port *port)
+{
+       int i;
+       int room = 0;
+       struct moschip_port *mos7840_port;
+
+       dbg("%s \n", " mos7840_write_room:entering ...........");
+
+       if (mos7840_port_paranoia_check(port, __FUNCTION__)) {
+               dbg("%s", "Invalid port \n");
+               dbg("%s \n", " mos7840_write_room:leaving ...........");
+               return -1;
+       }
+
+       mos7840_port = mos7840_get_port_private(port);
+       if (mos7840_port == NULL) {
+               dbg("%s \n", "mos7840_break:leaving ...........");
+               return -1;
+       }
+
+       for (i = 0; i < NUM_URBS; ++i) {
+               if (mos7840_port->write_urb_pool[i]->status != -EINPROGRESS) {
+                       room += URB_TRANSFER_BUFFER_SIZE;
+               }
+       }
+
+       dbg("%s - returns %d", __FUNCTION__, room);
+       return (room);
+
+}
+
+/*****************************************************************************
+ * mos7840_write
+ *     this function is called by the tty driver when data should be written to
+ *     the port.
+ *     If successful, we return the number of bytes written, otherwise we
+ *      return a negative error number.
+ *****************************************************************************/
+
+static int mos7840_write(struct usb_serial_port *port,
+                        const unsigned char *data, int count)
+{
+       int status;
+       int i;
+       int bytes_sent = 0;
+       int transfer_size;
+       int from_user = 0;
+
+       struct moschip_port *mos7840_port;
+       struct usb_serial *serial;
+       struct urb *urb;
+       //__u16 Data;
+       const unsigned char *current_position = data;
+       unsigned char *data1;
+       dbg("%s \n", "entering ...........");
+       //dbg("mos7840_write: mos7840_port->shadowLCR is %x\n",mos7840_port->shadowLCR);
+
+#ifdef NOTMOS7840
+       Data = 0x00;
+       status = 0;
+       status = mos7840_get_uart_reg(port, LINE_CONTROL_REGISTER, &Data);
+       mos7840_port->shadowLCR = Data;
+       dbg("mos7840_write: LINE_CONTROL_REGISTER is %x\n", Data);
+       dbg("mos7840_write: mos7840_port->shadowLCR is %x\n",
+           mos7840_port->shadowLCR);
+
+       //Data = 0x03;
+       //status = mos7840_set_uart_reg(port,LINE_CONTROL_REGISTER,Data);
+       //mos7840_port->shadowLCR=Data;//Need to add later
+
+       Data |= SERIAL_LCR_DLAB;        //data latch enable in LCR 0x80
+       status = 0;
+       status = mos7840_set_uart_reg(port, LINE_CONTROL_REGISTER, Data);
+
+       //Data = 0x0c;
+       //status = mos7840_set_uart_reg(port,DIVISOR_LATCH_LSB,Data);
+       Data = 0x00;
+       status = 0;
+       status = mos7840_get_uart_reg(port, DIVISOR_LATCH_LSB, &Data);
+       dbg("mos7840_write:DLL value is %x\n", Data);
+
+       Data = 0x0;
+       status = 0;
+       status = mos7840_get_uart_reg(port, DIVISOR_LATCH_MSB, &Data);
+       dbg("mos7840_write:DLM value is %x\n", Data);
+
+       Data = Data & ~SERIAL_LCR_DLAB;
+       dbg("mos7840_write: mos7840_port->shadowLCR is %x\n",
+           mos7840_port->shadowLCR);
+       status = 0;
+       status = mos7840_set_uart_reg(port, LINE_CONTROL_REGISTER, Data);
+#endif
+
+       if (mos7840_port_paranoia_check(port, __FUNCTION__)) {
+               dbg("%s", "Port Paranoia failed \n");
+               return -1;
+       }
+
+       serial = port->serial;
+       if (mos7840_serial_paranoia_check(serial, __FUNCTION__)) {
+               dbg("%s", "Serial Paranoia failed \n");
+               return -1;
+       }
+
+       mos7840_port = mos7840_get_port_private(port);
+       if (mos7840_port == NULL) {
+               dbg("%s", "mos7840_port is NULL\n");
+               return -1;
+       }
+
+       /* try to find a free urb in the list */
+       urb = NULL;
+
+       for (i = 0; i < NUM_URBS; ++i) {
+               if (mos7840_port->write_urb_pool[i]->status != -EINPROGRESS) {
+                       urb = mos7840_port->write_urb_pool[i];
+                       dbg("\nURB:%d", i);
+                       break;
+               }
+       }
+
+       if (urb == NULL) {
+               dbg("%s - no more free urbs", __FUNCTION__);
+               goto exit;
+       }
+
+       if (urb->transfer_buffer == NULL) {
+               urb->transfer_buffer =
+                   kmalloc(URB_TRANSFER_BUFFER_SIZE, GFP_KERNEL);
+
+               if (urb->transfer_buffer == NULL) {
+                       err("%s no more kernel memory...", __FUNCTION__);
+                       goto exit;
+               }
+       }
+       transfer_size = min(count, URB_TRANSFER_BUFFER_SIZE);
+
+       if (from_user) {
+               if (copy_from_user
+                   (urb->transfer_buffer, current_position, transfer_size)) {
+                       bytes_sent = -EFAULT;
+                       goto exit;
+               }
+       } else {
+               memcpy(urb->transfer_buffer, current_position, transfer_size);
+       }
+
+       /* fill urb with data and submit  */
+       usb_fill_bulk_urb(urb,
+                         serial->dev,
+                         usb_sndbulkpipe(serial->dev,
+                                         port->bulk_out_endpointAddress),
+                         urb->transfer_buffer,
+                         transfer_size,
+                         mos7840_bulk_out_data_callback, mos7840_port);
+
+       data1 = urb->transfer_buffer;
+       dbg("\nbulkout endpoint is %d", port->bulk_out_endpointAddress);
+
+       /* send it down the pipe */
+       status = usb_submit_urb(urb, GFP_ATOMIC);
+
+       if (status) {
+               err("%s - usb_submit_urb(write bulk) failed with status = %d",
+                   __FUNCTION__, status);
+               bytes_sent = status;
+               goto exit;
+       }
+       bytes_sent = transfer_size;
+       mos7840_port->icount.tx += transfer_size;
+       dbg("mos7840_port->icount.tx is %d:\n", mos7840_port->icount.tx);
+      exit:
+
+       return bytes_sent;
+
+}
+
+/*****************************************************************************
+ * mos7840_throttle
+ *     this function is called by the tty driver when it wants to stop the data
+ *     being read from the port.
+ *****************************************************************************/
+
+static void mos7840_throttle(struct usb_serial_port *port)
+{
+       struct moschip_port *mos7840_port;
+       struct tty_struct *tty;
+       int status;
+
+       if (mos7840_port_paranoia_check(port, __FUNCTION__)) {
+               dbg("%s", "Invalid port \n");
+               return;
+       }
+
+       dbg("- port %d\n", port->number);
+
+       mos7840_port = mos7840_get_port_private(port);
+
+       if (mos7840_port == NULL)
+               return;
+
+       if (!mos7840_port->open) {
+               dbg("%s\n", "port not opened");
+               return;
+       }
+
+       dbg("%s", "Entering .......... \n");
+
+       tty = port->tty;
+       if (!tty) {
+               dbg("%s - no tty available", __FUNCTION__);
+               return;
+       }
+
+       /* if we are implementing XON/XOFF, send the stop character */
+       if (I_IXOFF(tty)) {
+               unsigned char stop_char = STOP_CHAR(tty);
+               status = mos7840_write(port, &stop_char, 1);
+               if (status <= 0) {
+                       return;
+               }
+       }
+
+       /* if we are implementing RTS/CTS, toggle that line */
+       if (tty->termios->c_cflag & CRTSCTS) {
+               mos7840_port->shadowMCR &= ~MCR_RTS;
+               status = 0;
+               status =
+                   mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER,
+                                        mos7840_port->shadowMCR);
+
+               if (status < 0) {
+                       return;
+               }
+       }
+
+       return;
+}
+
+/*****************************************************************************
+ * mos7840_unthrottle
+ *     this function is called by the tty driver when it wants to resume the data
+ *     being read from the port (called after SerialThrottle is called)
+ *****************************************************************************/
+static void mos7840_unthrottle(struct usb_serial_port *port)
+{
+       struct tty_struct *tty;
+       int status;
+       struct moschip_port *mos7840_port = mos7840_get_port_private(port);
+
+       if (mos7840_port_paranoia_check(port, __FUNCTION__)) {
+               dbg("%s", "Invalid port \n");
+               return;
+       }
+
+       if (mos7840_port == NULL)
+               return;
+
+       if (!mos7840_port->open) {
+               dbg("%s - port not opened", __FUNCTION__);
+               return;
+       }
+
+       dbg("%s", "Entering .......... \n");
+
+       tty = port->tty;
+       if (!tty) {
+               dbg("%s - no tty available", __FUNCTION__);
+               return;
+       }
+
+       /* if we are implementing XON/XOFF, send the start character */
+       if (I_IXOFF(tty)) {
+               unsigned char start_char = START_CHAR(tty);
+               status = mos7840_write(port, &start_char, 1);
+               if (status <= 0) {
+                       return;
+               }
+       }
+
+       /* if we are implementing RTS/CTS, toggle that line */
+       if (tty->termios->c_cflag & CRTSCTS) {
+               mos7840_port->shadowMCR |= MCR_RTS;
+               status = 0;
+               status =
+                   mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER,
+                                        mos7840_port->shadowMCR);
+               if (status < 0) {
+                       return;
+               }
+       }
+
+       return;
+}
+
+static int mos7840_tiocmget(struct usb_serial_port *port, struct file *file)
+{
+       struct moschip_port *mos7840_port;
+       unsigned int result;
+       __u16 msr;
+       __u16 mcr;
+       int status = 0;
+       mos7840_port = mos7840_get_port_private(port);
+
+       dbg("%s - port %d", __FUNCTION__, port->number);
+
+       if (mos7840_port == NULL)
+               return -ENODEV;
+
+       status = mos7840_get_uart_reg(port, MODEM_STATUS_REGISTER, &msr);
+       status = mos7840_get_uart_reg(port, MODEM_CONTROL_REGISTER, &mcr);
+       result = ((mcr & MCR_DTR) ? TIOCM_DTR : 0)
+           | ((mcr & MCR_RTS) ? TIOCM_RTS : 0)
+           | ((mcr & MCR_LOOPBACK) ? TIOCM_LOOP : 0)
+           | ((msr & MOS7840_MSR_CTS) ? TIOCM_CTS : 0)
+           | ((msr & MOS7840_MSR_CD) ? TIOCM_CAR : 0)
+           | ((msr & MOS7840_MSR_RI) ? TIOCM_RI : 0)
+           | ((msr & MOS7840_MSR_DSR) ? TIOCM_DSR : 0);
+
+       dbg("%s - 0x%04X", __FUNCTION__, result);
+
+       return result;
+}
+
+static int mos7840_tiocmset(struct usb_serial_port *port, struct file *file,
+                           unsigned int set, unsigned int clear)
+{
+       struct moschip_port *mos7840_port;
+       unsigned int mcr;
+       unsigned int status;
+
+       dbg("%s - port %d", __FUNCTION__, port->number);
+
+       mos7840_port = mos7840_get_port_private(port);
+
+       if (mos7840_port == NULL)
+               return -ENODEV;
+
+       mcr = mos7840_port->shadowMCR;
+       if (clear & TIOCM_RTS)
+               mcr &= ~MCR_RTS;
+       if (clear & TIOCM_DTR)
+               mcr &= ~MCR_DTR;
+       if (clear & TIOCM_LOOP)
+               mcr &= ~MCR_LOOPBACK;
+
+       if (set & TIOCM_RTS)
+               mcr |= MCR_RTS;
+       if (set & TIOCM_DTR)
+               mcr |= MCR_DTR;
+       if (set & TIOCM_LOOP)
+               mcr |= MCR_LOOPBACK;
+
+       mos7840_port->shadowMCR = mcr;
+
+       status = 0;
+       status = mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER, mcr);
+       if (status < 0) {
+               dbg("setting MODEM_CONTROL_REGISTER Failed\n");
+               return -1;
+       }
+
+       return 0;
+}
+
+/*****************************************************************************
+ * mos7840_calc_baud_rate_divisor
+ *     this function calculates the proper baud rate divisor for the specified
+ *     baud rate.
+ *****************************************************************************/
+static int mos7840_calc_baud_rate_divisor(int baudRate, int *divisor,
+                                         __u16 * clk_sel_val)
+{
+
+       dbg("%s - %d", __FUNCTION__, baudRate);
+
+       if (baudRate <= 115200) {
+               *divisor = 115200 / baudRate;
+               *clk_sel_val = 0x0;
+       }
+       if ((baudRate > 115200) && (baudRate <= 230400)) {
+               *divisor = 230400 / baudRate;
+               *clk_sel_val = 0x10;
+       } else if ((baudRate > 230400) && (baudRate <= 403200)) {
+               *divisor = 403200 / baudRate;
+               *clk_sel_val = 0x20;
+       } else if ((baudRate > 403200) && (baudRate <= 460800)) {
+               *divisor = 460800 / baudRate;
+               *clk_sel_val = 0x30;
+       } else if ((baudRate > 460800) && (baudRate <= 806400)) {
+               *divisor = 806400 / baudRate;
+               *clk_sel_val = 0x40;
+       } else if ((baudRate > 806400) && (baudRate <= 921600)) {
+               *divisor = 921600 / baudRate;
+               *clk_sel_val = 0x50;
+       } else if ((baudRate > 921600) && (baudRate <= 1572864)) {
+               *divisor = 1572864 / baudRate;
+               *clk_sel_val = 0x60;
+       } else if ((baudRate > 1572864) && (baudRate <= 3145728)) {
+               *divisor = 3145728 / baudRate;
+               *clk_sel_val = 0x70;
+       }
+       return 0;
+
+#ifdef NOTMCS7840
+
+       for (i = 0; i < ARRAY_SIZE(mos7840_divisor_table); i++) {
+               if (mos7840_divisor_table[i].BaudRate == baudrate) {
+                       *divisor = mos7840_divisor_table[i].Divisor;
+                       return 0;
+               }
+       }
+
+       /* After trying for all the standard baud rates    *
+        * Try calculating the divisor for this baud rate  */
+
+       if (baudrate > 75 && baudrate < 230400) {
+               /* get the divisor */
+               custom = (__u16) (230400L / baudrate);
+
+               /* Check for round off */
+               round1 = (__u16) (2304000L / baudrate);
+               round = (__u16) (round1 - (custom * 10));
+               if (round > 4) {
+                       custom++;
+               }
+               *divisor = custom;
+
+               dbg(" Baud %d = %d\n", baudrate, custom);
+               return 0;
+       }
+
+       dbg("%s\n", " Baud calculation Failed...");
+       return -1;
+#endif
+}
+
+/*****************************************************************************
+ * mos7840_send_cmd_write_baud_rate
+ *     this function sends the proper command to change the baud rate of the
+ *     specified port.
+ *****************************************************************************/
+
+static int mos7840_send_cmd_write_baud_rate(struct moschip_port *mos7840_port,
+                                           int baudRate)
+{
+       int divisor = 0;
+       int status;
+       __u16 Data;
+       unsigned char number;
+       __u16 clk_sel_val;
+       struct usb_serial_port *port;
+
+       if (mos7840_port == NULL)
+               return -1;
+
+       port = (struct usb_serial_port *)mos7840_port->port;
+       if (mos7840_port_paranoia_check(port, __FUNCTION__)) {
+               dbg("%s", "Invalid port \n");
+               return -1;
+       }
+
+       if (mos7840_serial_paranoia_check(port->serial, __FUNCTION__)) {
+               dbg("%s", "Invalid Serial \n");
+               return -1;
+       }
+
+       dbg("%s", "Entering .......... \n");
+
+       number = mos7840_port->port->number - mos7840_port->port->serial->minor;
+
+       dbg("%s - port = %d, baud = %d", __FUNCTION__,
+           mos7840_port->port->number, baudRate);
+       //reset clk_uart_sel in spregOffset
+       if (baudRate > 115200) {
+#ifdef HW_flow_control
+               //NOTE: need to see the pther register to modify
+               //setting h/w flow control bit to 1;
+               status = 0;
+               Data = 0x2b;
+               mos7840_port->shadowMCR = Data;
+               status =
+                   mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER, Data);
+               if (status < 0) {
+                       dbg("Writing spreg failed in set_serial_baud\n");
+                       return -1;
+               }
+#endif
+
+       } else {
+#ifdef HW_flow_control
+               //setting h/w flow control bit to 0;
+               status = 0;
+               Data = 0xb;
+               mos7840_port->shadowMCR = Data;
+               status =
+                   mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER, Data);
+               if (status < 0) {
+                       dbg("Writing spreg failed in set_serial_baud\n");
+                       return -1;
+               }
+#endif
+
+       }
+
+       if (1)                  //baudRate <= 115200)
+       {
+               clk_sel_val = 0x0;
+               Data = 0x0;
+               status = 0;
+               status =
+                   mos7840_calc_baud_rate_divisor(baudRate, &divisor,
+                                                  &clk_sel_val);
+               status =
+                   mos7840_get_reg_sync(port, mos7840_port->SpRegOffset,
+                                        &Data);
+               if (status < 0) {
+                       dbg("reading spreg failed in set_serial_baud\n");
+                       return -1;
+               }
+               Data = (Data & 0x8f) | clk_sel_val;
+               status = 0;
+               status =
+                   mos7840_set_reg_sync(port, mos7840_port->SpRegOffset, Data);
+               if (status < 0) {
+                       dbg("Writing spreg failed in set_serial_baud\n");
+                       return -1;
+               }
+               /* Calculate the Divisor */
+
+               if (status) {
+                       err("%s - bad baud rate", __FUNCTION__);
+                       dbg("%s\n", "bad baud rate");
+                       return status;
+               }
+               /* Enable access to divisor latch */
+               Data = mos7840_port->shadowLCR | SERIAL_LCR_DLAB;
+               mos7840_port->shadowLCR = Data;
+               mos7840_set_uart_reg(port, LINE_CONTROL_REGISTER, Data);
+
+               /* Write the divisor */
+               Data = (unsigned char)(divisor & 0xff);
+               dbg("set_serial_baud Value to write DLL is %x\n", Data);
+               mos7840_set_uart_reg(port, DIVISOR_LATCH_LSB, Data);
+
+               Data = (unsigned char)((divisor & 0xff00) >> 8);
+               dbg("set_serial_baud Value to write DLM is %x\n", Data);
+               mos7840_set_uart_reg(port, DIVISOR_LATCH_MSB, Data);
+
+               /* Disable access to divisor latch */
+               Data = mos7840_port->shadowLCR & ~SERIAL_LCR_DLAB;
+               mos7840_port->shadowLCR = Data;
+               mos7840_set_uart_reg(port, LINE_CONTROL_REGISTER, Data);
+
+       }
+
+       return status;
+}
+
+/*****************************************************************************
+ * mos7840_change_port_settings
+ *     This routine is called to set the UART on the device to match
+ *      the specified new settings.
+ *****************************************************************************/
+
+static void mos7840_change_port_settings(struct moschip_port *mos7840_port,
+                                        struct termios *old_termios)
+{
+       struct tty_struct *tty;
+       int baud;
+       unsigned cflag;
+       unsigned iflag;
+       __u8 lData;
+       __u8 lParity;
+       __u8 lStop;
+       int status;
+       __u16 Data;
+       struct usb_serial_port *port;
+       struct usb_serial *serial;
+
+       if (mos7840_port == NULL)
+               return;
+
+       port = (struct usb_serial_port *)mos7840_port->port;
+
+       if (mos7840_port_paranoia_check(port, __FUNCTION__)) {
+               dbg("%s", "Invalid port \n");
+               return;
+       }
+
+       if (mos7840_serial_paranoia_check(port->serial, __FUNCTION__)) {
+               dbg("%s", "Invalid Serial \n");
+               return;
+       }
+
+       serial = port->serial;
+
+       dbg("%s - port %d", __FUNCTION__, mos7840_port->port->number);
+
+       if (!mos7840_port->open) {
+               dbg("%s - port not opened", __FUNCTION__);
+               return;
+       }
+
+       tty = mos7840_port->port->tty;
+
+       if ((!tty) || (!tty->termios)) {
+               dbg("%s - no tty structures", __FUNCTION__);
+               return;
+       }
+
+       dbg("%s", "Entering .......... \n");
+
+       lData = LCR_BITS_8;
+       lStop = LCR_STOP_1;
+       lParity = LCR_PAR_NONE;
+
+       cflag = tty->termios->c_cflag;
+       iflag = tty->termios->c_iflag;
+
+       /* Change the number of bits */
+       if (cflag & CSIZE) {
+               switch (cflag & CSIZE) {
+               case CS5:
+                       lData = LCR_BITS_5;
+                       break;
+
+               case CS6:
+                       lData = LCR_BITS_6;
+                       break;
+
+               case CS7:
+                       lData = LCR_BITS_7;
+                       break;
+               default:
+               case CS8:
+                       lData = LCR_BITS_8;
+                       break;
+               }
+       }
+       /* Change the Parity bit */
+       if (cflag & PARENB) {
+               if (cflag & PARODD) {
+                       lParity = LCR_PAR_ODD;
+                       dbg("%s - parity = odd", __FUNCTION__);
+               } else {
+                       lParity = LCR_PAR_EVEN;
+                       dbg("%s - parity = even", __FUNCTION__);
+               }
+
+       } else {
+               dbg("%s - parity = none", __FUNCTION__);
+       }
+
+       if (cflag & CMSPAR) {
+               lParity = lParity | 0x20;
+       }
+
+       /* Change the Stop bit */
+       if (cflag & CSTOPB) {
+               lStop = LCR_STOP_2;
+               dbg("%s - stop bits = 2", __FUNCTION__);
+       } else {
+               lStop = LCR_STOP_1;
+               dbg("%s - stop bits = 1", __FUNCTION__);
+       }
+
+       /* Update the LCR with the correct value */
+       mos7840_port->shadowLCR &=
+           ~(LCR_BITS_MASK | LCR_STOP_MASK | LCR_PAR_MASK);
+       mos7840_port->shadowLCR |= (lData | lParity | lStop);
+
+       dbg("mos7840_change_port_settings mos7840_port->shadowLCR is %x\n",
+           mos7840_port->shadowLCR);
+       /* Disable Interrupts */
+       Data = 0x00;
+       mos7840_set_uart_reg(port, INTERRUPT_ENABLE_REGISTER, Data);
+
+       Data = 0x00;
+       mos7840_set_uart_reg(port, FIFO_CONTROL_REGISTER, Data);
+
+       Data = 0xcf;
+       mos7840_set_uart_reg(port, FIFO_CONTROL_REGISTER, Data);
+
+       /* Send the updated LCR value to the mos7840 */
+       Data = mos7840_port->shadowLCR;
+
+       mos7840_set_uart_reg(port, LINE_CONTROL_REGISTER, Data);
+
+       Data = 0x00b;
+       mos7840_port->shadowMCR = Data;
+       mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER, Data);
+       Data = 0x00b;
+       mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER, Data);
+
+       /* set up the MCR register and send it to the mos7840 */
+
+       mos7840_port->shadowMCR = MCR_MASTER_IE;
+       if (cflag & CBAUD) {
+               mos7840_port->shadowMCR |= (MCR_DTR | MCR_RTS);
+       }
+
+       if (cflag & CRTSCTS) {
+               mos7840_port->shadowMCR |= (MCR_XON_ANY);
+
+       } else {
+               mos7840_port->shadowMCR &= ~(MCR_XON_ANY);
+       }
+
+       Data = mos7840_port->shadowMCR;
+       mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER, Data);
+
+       /* Determine divisor based on baud rate */
+       baud = tty_get_baud_rate(tty);
+
+       if (!baud) {
+               /* pick a default, any default... */
+               dbg("%s\n", "Picked default baud...");
+               baud = 9600;
+       }
+
+       dbg("%s - baud rate = %d", __FUNCTION__, baud);
+       status = mos7840_send_cmd_write_baud_rate(mos7840_port, baud);
+
+       /* Enable Interrupts */
+       Data = 0x0c;
+       mos7840_set_uart_reg(port, INTERRUPT_ENABLE_REGISTER, Data);
+
+       if (mos7840_port->read_urb->status != -EINPROGRESS) {
+               mos7840_port->read_urb->dev = serial->dev;
+
+               status = usb_submit_urb(mos7840_port->read_urb, GFP_ATOMIC);
+
+               if (status) {
+                       dbg(" usb_submit_urb(read bulk) failed, status = %d",
+                           status);
+               }
+       }
+       wake_up(&mos7840_port->delta_msr_wait);
+       mos7840_port->delta_msr_cond = 1;
+       dbg("mos7840_change_port_settings mos7840_port->shadowLCR is End %x\n",
+           mos7840_port->shadowLCR);
+
+       return;
+}
+
+/*****************************************************************************
+ * mos7840_set_termios
+ *     this function is called by the tty driver when it wants to change
+ *     the termios structure
+ *****************************************************************************/
+
+static void mos7840_set_termios(struct usb_serial_port *port,
+                               struct termios *old_termios)
+{
+       int status;
+       unsigned int cflag;
+       struct usb_serial *serial;
+       struct moschip_port *mos7840_port;
+       struct tty_struct *tty;
+       dbg("mos7840_set_termios: START\n");
+       if (mos7840_port_paranoia_check(port, __FUNCTION__)) {
+               dbg("%s", "Invalid port \n");
+               return;
+       }
+
+       serial = port->serial;
+
+       if (mos7840_serial_paranoia_check(serial, __FUNCTION__)) {
+               dbg("%s", "Invalid Serial \n");
+               return;
+       }
+
+       mos7840_port = mos7840_get_port_private(port);
+
+       if (mos7840_port == NULL)
+               return;
+
+       tty = port->tty;
+
+       if (!port->tty || !port->tty->termios) {
+               dbg("%s - no tty or termios", __FUNCTION__);
+               return;
+       }
+
+       if (!mos7840_port->open) {
+               dbg("%s - port not opened", __FUNCTION__);
+               return;
+       }
+
+       dbg("%s\n", "setting termios - ");
+
+       cflag = tty->termios->c_cflag;
+
+       if (!cflag) {
+               dbg("%s %s\n", __FUNCTION__, "cflag is NULL");
+               return;
+       }
+
+       /* check that they really want us to change something */
+       if (old_termios) {
+               if ((cflag == old_termios->c_cflag) &&
+                   (RELEVANT_IFLAG(tty->termios->c_iflag) ==
+                    RELEVANT_IFLAG(old_termios->c_iflag))) {
+                       dbg("%s\n", "Nothing to change");
+                       return;
+               }
+       }
+
+       dbg("%s - clfag %08x iflag %08x", __FUNCTION__,
+           tty->termios->c_cflag, RELEVANT_IFLAG(tty->termios->c_iflag));
+
+       if (old_termios) {
+               dbg("%s - old clfag %08x old iflag %08x", __FUNCTION__,
+                   old_termios->c_cflag, RELEVANT_IFLAG(old_termios->c_iflag));
+       }
+
+       dbg("%s - port %d", __FUNCTION__, port->number);
+
+       /* change the port settings to the new ones specified */
+
+       mos7840_change_port_settings(mos7840_port, old_termios);
+
+       if (!mos7840_port->read_urb) {
+               dbg("%s", "URB KILLED !!!!!\n");
+               return;
+       }
+
+       if (mos7840_port->read_urb->status != -EINPROGRESS) {
+               mos7840_port->read_urb->dev = serial->dev;
+               status = usb_submit_urb(mos7840_port->read_urb, GFP_ATOMIC);
+               if (status) {
+                       dbg(" usb_submit_urb(read bulk) failed, status = %d",
+                           status);
+               }
+       }
+       return;
+}
+
+/*****************************************************************************
+ * mos7840_get_lsr_info - get line status register info
+ *
+ * Purpose: Let user call ioctl() to get info when the UART physically
+ *         is emptied.  On bus types like RS485, the transmitter must
+ *         release the bus after transmitting. This must be done when
+ *         the transmit shift register is empty, not be done when the
+ *         transmit holding register is empty.  This functionality
+ *         allows an RS485 driver to be written in user space.
+ *****************************************************************************/
+
+static int mos7840_get_lsr_info(struct moschip_port *mos7840_port,
+                               unsigned int *value)
+{
+       int count;
+       unsigned int result = 0;
+
+       count = mos7840_chars_in_buffer(mos7840_port->port);
+       if (count == 0) {
+               dbg("%s -- Empty", __FUNCTION__);
+               result = TIOCSER_TEMT;
+       }
+
+       if (copy_to_user(value, &result, sizeof(int)))
+               return -EFAULT;
+       return 0;
+}
+
+/*****************************************************************************
+ * mos7840_get_bytes_avail - get number of bytes available
+ *
+ * Purpose: Let user call ioctl to get the count of number of bytes available.
+ *****************************************************************************/
+
+static int mos7840_get_bytes_avail(struct moschip_port *mos7840_port,
+                                  unsigned int *value)
+{
+       unsigned int result = 0;
+       struct tty_struct *tty = mos7840_port->port->tty;
+
+       if (!tty)
+               return -ENOIOCTLCMD;
+
+       result = tty->read_cnt;
+
+       dbg("%s(%d) = %d", __FUNCTION__, mos7840_port->port->number, result);
+       if (copy_to_user(value, &result, sizeof(int)))
+               return -EFAULT;
+
+       return -ENOIOCTLCMD;
+}
+
+/*****************************************************************************
+ * mos7840_set_modem_info
+ *      function to set modem info
+ *****************************************************************************/
+
+static int mos7840_set_modem_info(struct moschip_port *mos7840_port,
+                                 unsigned int cmd, unsigned int *value)
+{
+       unsigned int mcr;
+       unsigned int arg;
+       __u16 Data;
+       int status;
+       struct usb_serial_port *port;
+
+       if (mos7840_port == NULL)
+               return -1;
+
+       port = (struct usb_serial_port *)mos7840_port->port;
+       if (mos7840_port_paranoia_check(port, __FUNCTION__)) {
+               dbg("%s", "Invalid port \n");
+               return -1;
+       }
+
+       mcr = mos7840_port->shadowMCR;
+
+       if (copy_from_user(&arg, value, sizeof(int)))
+               return -EFAULT;
+
+       switch (cmd) {
+       case TIOCMBIS:
+               if (arg & TIOCM_RTS)
+                       mcr |= MCR_RTS;
+               if (arg & TIOCM_DTR)
+                       mcr |= MCR_RTS;
+               if (arg & TIOCM_LOOP)
+                       mcr |= MCR_LOOPBACK;
+               break;
+
+       case TIOCMBIC:
+               if (arg & TIOCM_RTS)
+                       mcr &= ~MCR_RTS;
+               if (arg & TIOCM_DTR)
+                       mcr &= ~MCR_RTS;
+               if (arg & TIOCM_LOOP)
+                       mcr &= ~MCR_LOOPBACK;
+               break;
+
+       case TIOCMSET:
+               /* turn off the RTS and DTR and LOOPBACK
+                * and then only turn on what was asked to */
+               mcr &= ~(MCR_RTS | MCR_DTR | MCR_LOOPBACK);
+               mcr |= ((arg & TIOCM_RTS) ? MCR_RTS : 0);
+               mcr |= ((arg & TIOCM_DTR) ? MCR_DTR : 0);
+               mcr |= ((arg & TIOCM_LOOP) ? MCR_LOOPBACK : 0);
+               break;
+       }
+
+       mos7840_port->shadowMCR = mcr;
+
+       Data = mos7840_port->shadowMCR;
+       status = 0;
+       status = mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER, Data);
+       if (status < 0) {
+               dbg("setting MODEM_CONTROL_REGISTER Failed\n");
+               return -1;
+       }
+
+       return 0;
+}
+
+/*****************************************************************************
+ * mos7840_get_modem_info
+ *      function to get modem info
+ *****************************************************************************/
+
+static int mos7840_get_modem_info(struct moschip_port *mos7840_port,
+                                 unsigned int *value)
+{
+       unsigned int result = 0;
+       __u16 msr;
+       unsigned int mcr = mos7840_port->shadowMCR;
+       int status = 0;
+       status =
+           mos7840_get_uart_reg(mos7840_port->port, MODEM_STATUS_REGISTER,
+                                &msr);
+       result = ((mcr & MCR_DTR) ? TIOCM_DTR : 0)      /* 0x002 */
+           |((mcr & MCR_RTS) ? TIOCM_RTS : 0)  /* 0x004 */
+           |((msr & MOS7840_MSR_CTS) ? TIOCM_CTS : 0)  /* 0x020 */
+           |((msr & MOS7840_MSR_CD) ? TIOCM_CAR : 0)   /* 0x040 */
+           |((msr & MOS7840_MSR_RI) ? TIOCM_RI : 0)    /* 0x080 */
+           |((msr & MOS7840_MSR_DSR) ? TIOCM_DSR : 0); /* 0x100 */
+
+       dbg("%s -- %x", __FUNCTION__, result);
+
+       if (copy_to_user(value, &result, sizeof(int)))
+               return -EFAULT;
+       return 0;
+}
+
+/*****************************************************************************
+ * mos7840_get_serial_info
+ *      function to get information about serial port
+ *****************************************************************************/
+
+static int mos7840_get_serial_info(struct moschip_port *mos7840_port,
+                                  struct serial_struct *retinfo)
+{
+       struct serial_struct tmp;
+
+       if (mos7840_port == NULL)
+               return -1;
+
+       if (!retinfo)
+               return -EFAULT;
+
+       memset(&tmp, 0, sizeof(tmp));
+
+       tmp.type = PORT_16550A;
+       tmp.line = mos7840_port->port->serial->minor;
+       tmp.port = mos7840_port->port->number;
+       tmp.irq = 0;
+       tmp.flags = ASYNC_SKIP_TEST | ASYNC_AUTO_IRQ;
+       tmp.xmit_fifo_size = NUM_URBS * URB_TRANSFER_BUFFER_SIZE;
+       tmp.baud_base = 9600;
+       tmp.close_delay = 5 * HZ;
+       tmp.closing_wait = 30 * HZ;
+
+       if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
+               return -EFAULT;
+       return 0;
+}
+
+/*****************************************************************************
+ * SerialIoctl
+ *     this function handles any ioctl calls to the driver
+ *****************************************************************************/
+
+static int mos7840_ioctl(struct usb_serial_port *port, struct file *file,
+                        unsigned int cmd, unsigned long arg)
+{
+       struct moschip_port *mos7840_port;
+       struct tty_struct *tty;
+
+       struct async_icount cnow;
+       struct async_icount cprev;
+       struct serial_icounter_struct icount;
+       int mosret = 0;
+       int retval;
+       struct tty_ldisc *ld;
+
+       if (mos7840_port_paranoia_check(port, __FUNCTION__)) {
+               dbg("%s", "Invalid port \n");
+               return -1;
+       }
+
+       mos7840_port = mos7840_get_port_private(port);
+       tty = mos7840_port->port->tty;
+
+       if (mos7840_port == NULL)
+               return -1;
+
+       dbg("%s - port %d, cmd = 0x%x", __FUNCTION__, port->number, cmd);
+
+       switch (cmd) {
+               /* return number of bytes available */
+
+       case TIOCINQ:
+               dbg("%s (%d) TIOCINQ", __FUNCTION__, port->number);
+               return mos7840_get_bytes_avail(mos7840_port,
+                                              (unsigned int *)arg);
+               break;
+
+       case TIOCOUTQ:
+               dbg("%s (%d) TIOCOUTQ", __FUNCTION__, port->number);
+               return put_user(tty->driver->chars_in_buffer ?
+                               tty->driver->chars_in_buffer(tty) : 0,
+                               (int __user *)arg);
+               break;
+
+       case TCFLSH:
+               retval = tty_check_change(tty);
+               if (retval)
+                       return retval;
+
+               ld = tty_ldisc_ref(tty);
+               switch (arg) {
+               case TCIFLUSH:
+                       if (ld && ld->flush_buffer)
+                               ld->flush_buffer(tty);
+                       break;
+               case TCIOFLUSH:
+                       if (ld && ld->flush_buffer)
+                               ld->flush_buffer(tty);
+                       /* fall through */
+               case TCOFLUSH:
+                       if (tty->driver->flush_buffer)
+                               tty->driver->flush_buffer(tty);
+                       break;
+               default:
+                       tty_ldisc_deref(ld);
+                       return -EINVAL;
+               }
+               tty_ldisc_deref(ld);
+               return 0;
+
+       case TCGETS:
+               if (kernel_termios_to_user_termios
+                   ((struct termios __user *)arg, tty->termios))
+                       return -EFAULT;
+               return 0;
+
+       case TIOCSERGETLSR:
+               dbg("%s (%d) TIOCSERGETLSR", __FUNCTION__, port->number);
+               return mos7840_get_lsr_info(mos7840_port, (unsigned int *)arg);
+               return 0;
+
+       case TIOCMBIS:
+       case TIOCMBIC:
+       case TIOCMSET:
+               dbg("%s (%d) TIOCMSET/TIOCMBIC/TIOCMSET", __FUNCTION__,
+                   port->number);
+               mosret =
+                   mos7840_set_modem_info(mos7840_port, cmd,
+                                          (unsigned int *)arg);
+               return mosret;
+
+       case TIOCMGET:
+               dbg("%s (%d) TIOCMGET", __FUNCTION__, port->number);
+               return mos7840_get_modem_info(mos7840_port,
+                                             (unsigned int *)arg);
+
+       case TIOCGSERIAL:
+               dbg("%s (%d) TIOCGSERIAL", __FUNCTION__, port->number);
+               return mos7840_get_serial_info(mos7840_port,
+                                              (struct serial_struct *)arg);
+
+       case TIOCSSERIAL:
+               dbg("%s (%d) TIOCSSERIAL", __FUNCTION__, port->number);
+               break;
+
+       case TIOCMIWAIT:
+               dbg("%s (%d) TIOCMIWAIT", __FUNCTION__, port->number);
+               cprev = mos7840_port->icount;
+               while (1) {
+                       //interruptible_sleep_on(&mos7840_port->delta_msr_wait);
+                       mos7840_port->delta_msr_cond = 0;
+                       wait_event_interruptible(mos7840_port->delta_msr_wait,
+                                                (mos7840_port->
+                                                 delta_msr_cond == 1));
+
+                       /* see if a signal did it */
+                       if (signal_pending(current))
+                               return -ERESTARTSYS;
+                       cnow = mos7840_port->icount;
+                       if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr &&
+                           cnow.dcd == cprev.dcd && cnow.cts == cprev.cts)
+                               return -EIO;    /* no change => error */
+                       if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
+                           ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
+                           ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) ||
+                           ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
+                               return 0;
+                       }
+                       cprev = cnow;
+               }
+               /* NOTREACHED */
+               break;
+
+       case TIOCGICOUNT:
+               cnow = mos7840_port->icount;
+               icount.cts = cnow.cts;
+               icount.dsr = cnow.dsr;
+               icount.rng = cnow.rng;
+               icount.dcd = cnow.dcd;
+               icount.rx = cnow.rx;
+               icount.tx = cnow.tx;
+               icount.frame = cnow.frame;
+               icount.overrun = cnow.overrun;
+               icount.parity = cnow.parity;
+               icount.brk = cnow.brk;
+               icount.buf_overrun = cnow.buf_overrun;
+
+               dbg("%s (%d) TIOCGICOUNT RX=%d, TX=%d", __FUNCTION__,
+                   port->number, icount.rx, icount.tx);
+               if (copy_to_user((void *)arg, &icount, sizeof(icount)))
+                       return -EFAULT;
+               return 0;
+
+       case TIOCEXBAUD:
+               return 0;
+       default:
+               break;
+       }
+
+       return -ENOIOCTLCMD;
+}
+
+static int mos7840_calc_num_ports(struct usb_serial *serial)
+{
+
+       dbg("numberofendpoints: %d \n",
+           (int)serial->interface->cur_altsetting->desc.bNumEndpoints);
+       dbg("numberofendpoints: %d \n",
+           (int)serial->interface->altsetting->desc.bNumEndpoints);
+       if (serial->interface->cur_altsetting->desc.bNumEndpoints == 5) {
+               mos7840_num_ports = 2;
+               serial->type->num_ports = 2;
+       } else if (serial->interface->cur_altsetting->desc.bNumEndpoints == 9) {
+               mos7840_num_ports = 4;
+               serial->type->num_bulk_in = 4;
+               serial->type->num_bulk_out = 4;
+               serial->type->num_ports = 4;
+       }
+
+       return mos7840_num_ports;
+}
+
+/****************************************************************************
+ * mos7840_startup
+ ****************************************************************************/
+
+static int mos7840_startup(struct usb_serial *serial)
+{
+       struct moschip_port *mos7840_port;
+       struct usb_device *dev;
+       int i, status;
+
+       __u16 Data;
+       dbg("%s \n", " mos7840_startup :entering..........");
+
+       if (!serial) {
+               dbg("%s\n", "Invalid Handler");
+               return -1;
+       }
+
+       dev = serial->dev;
+
+       dbg("%s\n", "Entering...");
+
+       /* we set up the pointers to the endpoints in the mos7840_open *
+        * function, as the structures aren't created yet.             */
+
+       /* set up port private structures */
+       for (i = 0; i < serial->num_ports; ++i) {
+               mos7840_port = kmalloc(sizeof(struct moschip_port), GFP_KERNEL);
+               if (mos7840_port == NULL) {
+                       err("%s - Out of memory", __FUNCTION__);
+                       return -ENOMEM;
+               }
+               memset(mos7840_port, 0, sizeof(struct moschip_port));
+
+               /* Initialize all port interrupt end point to port 0 int endpoint *
+                * Our device has only one interrupt end point comman to all port */
+
+               mos7840_port->port = serial->port[i];
+               mos7840_set_port_private(serial->port[i], mos7840_port);
+
+               mos7840_port->port_num = ((serial->port[i]->number -
+                                          (serial->port[i]->serial->minor)) +
+                                         1);
+
+               if (mos7840_port->port_num == 1) {
+                       mos7840_port->SpRegOffset = 0x0;
+                       mos7840_port->ControlRegOffset = 0x1;
+                       mos7840_port->DcrRegOffset = 0x4;
+               } else if ((mos7840_port->port_num == 2)
+                          && (mos7840_num_ports == 4)) {
+                       mos7840_port->SpRegOffset = 0x8;
+                       mos7840_port->ControlRegOffset = 0x9;
+                       mos7840_port->DcrRegOffset = 0x16;
+               } else if ((mos7840_port->port_num == 2)
+                          && (mos7840_num_ports == 2)) {
+                       mos7840_port->SpRegOffset = 0xa;
+                       mos7840_port->ControlRegOffset = 0xb;
+                       mos7840_port->DcrRegOffset = 0x19;
+               } else if ((mos7840_port->port_num == 3)
+                          && (mos7840_num_ports == 4)) {
+                       mos7840_port->SpRegOffset = 0xa;
+                       mos7840_port->ControlRegOffset = 0xb;
+                       mos7840_port->DcrRegOffset = 0x19;
+               } else if ((mos7840_port->port_num == 4)
+                          && (mos7840_num_ports == 4)) {
+                       mos7840_port->SpRegOffset = 0xc;
+                       mos7840_port->ControlRegOffset = 0xd;
+                       mos7840_port->DcrRegOffset = 0x1c;
+               }
+               mos7840_dump_serial_port(mos7840_port);
+
+               mos7840_set_port_private(serial->port[i], mos7840_port);
+
+               //enable rx_disable bit in control register
+
+               status =
+                   mos7840_get_reg_sync(serial->port[i],
+                                        mos7840_port->ControlRegOffset, &Data);
+               if (status < 0) {
+                       dbg("Reading ControlReg failed status-0x%x\n", status);
+                       break;
+               } else
+                       dbg("ControlReg Reading success val is %x, status%d\n",
+                           Data, status);
+               Data |= 0x08;   //setting driver done bit
+               Data |= 0x04;   //sp1_bit to have cts change reflect in modem status reg
+
+               //Data |= 0x20; //rx_disable bit
+               status = 0;
+               status =
+                   mos7840_set_reg_sync(serial->port[i],
+                                        mos7840_port->ControlRegOffset, Data);
+               if (status < 0) {
+                       dbg("Writing ControlReg failed(rx_disable) status-0x%x\n", status);
+                       break;
+               } else
+                       dbg("ControlReg Writing success(rx_disable) status%d\n",
+                           status);
+
+               //Write default values in DCR (i.e 0x01 in DCR0, 0x05 in DCR2 and 0x24 in DCR3
+               Data = 0x01;
+               status = 0;
+               status =
+                   mos7840_set_reg_sync(serial->port[i],
+                                        (__u16) (mos7840_port->DcrRegOffset +
+                                                 0), Data);
+               if (status < 0) {
+                       dbg("Writing DCR0 failed status-0x%x\n", status);
+                       break;
+               } else
+                       dbg("DCR0 Writing success status%d\n", status);
+
+               Data = 0x05;
+               status = 0;
+               status =
+                   mos7840_set_reg_sync(serial->port[i],
+                                        (__u16) (mos7840_port->DcrRegOffset +
+                                                 1), Data);
+               if (status < 0) {
+                       dbg("Writing DCR1 failed status-0x%x\n", status);
+                       break;
+               } else
+                       dbg("DCR1 Writing success status%d\n", status);
+
+               Data = 0x24;
+               status = 0;
+               status =
+                   mos7840_set_reg_sync(serial->port[i],
+                                        (__u16) (mos7840_port->DcrRegOffset +
+                                                 2), Data);
+               if (status < 0) {
+                       dbg("Writing DCR2 failed status-0x%x\n", status);
+                       break;
+               } else
+                       dbg("DCR2 Writing success status%d\n", status);
+
+               // write values in clkstart0x0 and clkmulti 0x20
+               Data = 0x0;
+               status = 0;
+               status =
+                   mos7840_set_reg_sync(serial->port[i],
+                                        CLK_START_VALUE_REGISTER, Data);
+               if (status < 0) {
+                       dbg("Writing CLK_START_VALUE_REGISTER failed status-0x%x\n", status);
+                       break;
+               } else
+                       dbg("CLK_START_VALUE_REGISTER Writing success status%d\n", status);
+
+               Data = 0x20;
+               status = 0;
+               status =
+                   mos7840_set_reg_sync(serial->port[i], CLK_MULTI_REGISTER,
+                                        Data);
+               if (status < 0) {
+                       dbg("Writing CLK_MULTI_REGISTER failed status-0x%x\n",
+                           status);
+                       break;
+               } else
+                       dbg("CLK_MULTI_REGISTER Writing success status%d\n",
+                           status);
+
+               //write value 0x0 to scratchpad register
+               Data = 0x00;
+               status = 0;
+               status =
+                   mos7840_set_uart_reg(serial->port[i], SCRATCH_PAD_REGISTER,
+                                        Data);
+               if (status < 0) {
+                       dbg("Writing SCRATCH_PAD_REGISTER failed status-0x%x\n",
+                           status);
+                       break;
+               } else
+                       dbg("SCRATCH_PAD_REGISTER Writing success status%d\n",
+                           status);
+
+               //Zero Length flag register
+               if ((mos7840_port->port_num != 1)
+                   && (mos7840_num_ports == 2)) {
+
+                       Data = 0xff;
+                       status = 0;
+                       status = mos7840_set_reg_sync(serial->port[i],
+                                                     (__u16) (ZLP_REG1 +
+                                                              ((__u16)
+                                                               mos7840_port->
+                                                               port_num)),
+                                                     Data);
+                       dbg("ZLIP offset%x\n",
+                           (__u16) (ZLP_REG1 +
+                                    ((__u16) mos7840_port->port_num)));
+                       if (status < 0) {
+                               dbg("Writing ZLP_REG%d failed status-0x%x\n",
+                                   i + 2, status);
+                               break;
+                       } else
+                               dbg("ZLP_REG%d Writing success status%d\n",
+                                   i + 2, status);
+               } else {
+                       Data = 0xff;
+                       status = 0;
+                       status = mos7840_set_reg_sync(serial->port[i],
+                                                     (__u16) (ZLP_REG1 +
+                                                              ((__u16)
+                                                               mos7840_port->
+                                                               port_num) -
+                                                              0x1), Data);
+                       dbg("ZLIP offset%x\n",
+                           (__u16) (ZLP_REG1 +
+                                    ((__u16) mos7840_port->port_num) - 0x1));
+                       if (status < 0) {
+                               dbg("Writing ZLP_REG%d failed status-0x%x\n",
+                                   i + 1, status);
+                               break;
+                       } else
+                               dbg("ZLP_REG%d Writing success status%d\n",
+                                   i + 1, status);
+
+               }
+               mos7840_port->control_urb = usb_alloc_urb(0, SLAB_ATOMIC);
+               mos7840_port->ctrl_buf = kmalloc(16, GFP_KERNEL);
+
+       }
+
+       //Zero Length flag enable
+       Data = 0x0f;
+       status = 0;
+       status = mos7840_set_reg_sync(serial->port[0], ZLP_REG5, Data);
+       if (status < 0) {
+               dbg("Writing ZLP_REG5 failed status-0x%x\n", status);
+               return -1;
+       } else
+               dbg("ZLP_REG5 Writing success status%d\n", status);
+
+       /* setting configuration feature to one */
+       usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
+                       (__u8) 0x03, 0x00, 0x01, 0x00, 0x00, 0x00, 5 * HZ);
+       return 0;
+}
+
+/****************************************************************************
+ * mos7840_shutdown
+ *     This function is called whenever the device is removed from the usb bus.
+ ****************************************************************************/
+
+static void mos7840_shutdown(struct usb_serial *serial)
+{
+       int i;
+       struct moschip_port *mos7840_port;
+       dbg("%s \n", " shutdown :entering..........");
+
+       if (!serial) {
+               dbg("%s", "Invalid Handler \n");
+               return;
+       }
+
+       /*      check for the ports to be closed,close the ports and disconnect         */
+
+       /* free private structure allocated for serial port  *
+        * stop reads and writes on all ports                */
+
+       for (i = 0; i < serial->num_ports; ++i) {
+               mos7840_port = mos7840_get_port_private(serial->port[i]);
+               kfree(mos7840_port->ctrl_buf);
+               usb_kill_urb(mos7840_port->control_urb);
+               kfree(mos7840_port);
+               mos7840_set_port_private(serial->port[i], NULL);
+       }
+
+       dbg("%s\n", "Thank u :: ");
+
+}
+
+static struct usb_serial_driver moschip7840_4port_device = {
+       .driver = {
+                  .owner = THIS_MODULE,
+                  .name = "mos7840",
+                  },
+       .description = DRIVER_DESC,
+       .id_table = moschip_port_id_table,
+       .num_interrupt_in = 1,  //NUM_DONT_CARE,//1,
+#ifdef check
+       .num_bulk_in = 4,
+       .num_bulk_out = 4,
+       .num_ports = 4,
+#endif
+       .open = mos7840_open,
+       .close = mos7840_close,
+       .write = mos7840_write,
+       .write_room = mos7840_write_room,
+       .chars_in_buffer = mos7840_chars_in_buffer,
+       .throttle = mos7840_throttle,
+       .unthrottle = mos7840_unthrottle,
+       .calc_num_ports = mos7840_calc_num_ports,
+#ifdef MCSSerialProbe
+       .probe = mos7840_serial_probe,
+#endif
+       .ioctl = mos7840_ioctl,
+       .set_termios = mos7840_set_termios,
+       .break_ctl = mos7840_break,
+       .tiocmget = mos7840_tiocmget,
+       .tiocmset = mos7840_tiocmset,
+       .attach = mos7840_startup,
+       .shutdown = mos7840_shutdown,
+       .read_bulk_callback = mos7840_bulk_in_callback,
+       .read_int_callback = mos7840_interrupt_callback,
+};
+
+static struct usb_driver io_driver = {
+       .name = "mos7840",
+       .probe = usb_serial_probe,
+       .disconnect = usb_serial_disconnect,
+       .id_table = moschip_id_table_combined,
+};
+
+/****************************************************************************
+ * moschip7840_init
+ *     This is called by the module subsystem, or on startup to initialize us
+ ****************************************************************************/
+static int __init moschip7840_init(void)
+{
+       int retval;
+
+       dbg("%s \n", " mos7840_init :entering..........");
+
+       /* Register with the usb serial */
+       retval = usb_serial_register(&moschip7840_4port_device);
+
+       if (retval)
+               goto failed_port_device_register;
+
+       dbg("%s\n", "Entring...");
+       info(DRIVER_DESC " " DRIVER_VERSION);
+
+       /* Register with the usb */
+       retval = usb_register(&io_driver);
+
+       if (retval)
+               goto failed_usb_register;
+
+       if (retval == 0) {
+               dbg("%s\n", "Leaving...");
+               return 0;
+       }
+
+      failed_usb_register:
+       usb_serial_deregister(&moschip7840_4port_device);
+
+      failed_port_device_register:
+
+       return retval;
+}
+
+/****************************************************************************
+ * moschip7840_exit
+ *     Called when the driver is about to be unloaded.
+ ****************************************************************************/
+static void __exit moschip7840_exit(void)
+{
+
+       dbg("%s \n", " mos7840_exit :entering..........");
+
+       usb_deregister(&io_driver);
+
+       usb_serial_deregister(&moschip7840_4port_device);
+
+       dbg("%s\n", "Entring...");
+}
+
+module_init(moschip7840_init);
+module_exit(moschip7840_exit);
+
+/* Module information */
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");
+
+module_param(debug, bool, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(debug, "Debug enabled or not");